(L3). Measurements (in mm). Body length: 1.66–4.75. Body width (metathorax or abdominal segments I–II) 0.37–1.25. Head width: 0.30–0.66.

Body distinctly white to yellow. Body curved, slender, rounded in cross section. Setae on body thin, in different colouration, distinctly different in length; piliform, integument often with some asperities. Prothorax slightly smaller than meso- and metathorax. Spiracle placed between the pro- and mesothorax (see e.g., Gosik et al. 2016). Abdominal segments I–III(VI) of almost equal length, next abdominal segments decreasing gradually to the terminal parts of the body. Abdominal segment X reduced to three or four anal lobes of unequal size. Anus located terminally. Thoracic spiracles uni- or bicameral, eight abdominal spiracles unicameral, all spiracles functional, close to anterior margin of segment. Prothorax with eight to eleven prns; two ps; and one eus. Mesothorax with one prs, two or three pds; one or two as; three ss; one eps; one ps; and one eus. Chaetotaxy of metathorax almost identical to that of mesothorax. Each pedal area of thoracic segments well separated, with three to six pda. Abdominal segments I–VIII with one prs; three or four pds; two or three ss; two long eps; one ps; one lsts; and two eus. Abdominal segment IX with two to four ds; one or two ps; and two sts. Abdominal segment X without or with up to two minute ts.

Head capsule yellow to pale brown, rounded or flattened laterally, endocarinal line distinct, half or more than half the length of frons. Frontal sutures extended to antennae. One or two stemmata (st), anterior stemma in the form of a pigmented spot with convex cornea. Dorsum of the epicranium with five setae; des₁ located in the central part of epicranium, des₂ lateral, des₃ located anteriorly on epicranium close to frontal suture, des₄ often medially, des₅ located anterolaterally. Frons with three to five fs, fs₁ sometimes absent, fs₂ absent except one exception; fs₄ and fs₅ subequal. Head with two les, one or two ves, and one to five pes. Antennae located at the end of the frontal suture on each side, membranous and distinctly convex basal article bearing three or four sensilla and a conical sensorium, the later elongated, narrow. Clypeus trapezium-shaped, with one or two cls, and one sensillum (clss); all very close to margin with frons. Labrum with three lms; anterior margin bisinuated; lrs₁ placed posteromedially, lrs₂ anteromedially, lrs₃ posterolaterally. Epipharynx with three finger-like als; with two or three ams; and one or two mes; labral rods (lr) distinct, kidney-shaped. Mandibles distinctly broad, bifid, teeth of unequal height; slightly truncate; both setae piliform. Maxilla stipes with one stps, two pfs and one short to minute mbs; mala with six or seven finger-like dms; four or five vms; all vms distinctly shorter than dms. Maxillary palpi with two palpomeres; basal palpomere with one short mxps and two sensilla; distal palpomere with one sensillum and a group of microcuticular apical processes. Prelabium various in shape, with one prms; ligula with sinuate margin and two or three ligs; premental sclerite well sclerotised but without anterior and posterior extensions, U-shaped or cup-like. Labial palpi with one or two palpomeres; each of the palpomeres with one sensillum, distal palpomere with cuticular apical processes. Postlabium with three pms: pms₁ usually the shortest, placed anteromedially or anterolaterally, pms₂ the longest, placed laterally, and pms₃ short or medium, placed posterolaterally.

Measurements (in mm). Head width: 0.28–0.75. Body width: 0.90–2.15. Body length: 1.20–5.00.

Body stout or elongate; normally white, but sometimes yellowish; cuticle smooth. Rostrum various in length, from two to five times as long as wide. Antennae short or elongate. Pronotum 1.1–2.2 times as wide as long. Meso- and metanotum often equal in length. Abdominal segments I–(IV)VII of equal length; segment VIII almost semicircle, segment IX distinctly reduced. Spiracles on abdominal segments placed dorsolaterally; on segments I–V functional, on segment VI atrophied on next ones invisible. Urogomphi (ur) short or elongate.

Chaetotaxy often well developed, but sometimes almost invisible. Head capsule without or with one vs, without or with up to two sos, without or with up to two os. Rostrum without or with up to two rs, and without or with one pas. Pronotum without or with up to two as, without or with one ds, one or two sls, without or with up to two ls, and two to four pls. Dorsal parts of meso- and metathorax with two or three setae. Apex of femora normally with one short fes. Abdominal segments I–VIII without or with up to two setae laterally and without or with up to three setae ventrally. Dorsal parts of abdominal segments I–VII with three to seven setae; abdominal segment VIII with three to six setae dorsally. Abdominal segment IX without or with up to four micro-setae ventrally.

Larva. (1) cuticle of the body tuberculate; (2) pedal lobes prominent, clearly distinct; (3) abdominal segment X reduced to three anal lobes; (4) thoracic spiracle unicameral; (5) abdominal setae various in length, progressively longer from abdominal segment I to VIII; (6) abdominal segments I–VIII with four pds and two ss; (7) head white, rounded; (8) frontal suture weakly visible; (9) endocarina 4/5 length of frons; (10) des₄ short; (11) presence of fs₁; (12) absence of fs₂; (13) fs₃ very short; (14) head with one stemma; (15) absence of cls₁; (16) labial palpi one-segmented; (17) premental sclerite cup-like, posterior extension with short, dull apex; (18) surface of postlabium smooth.

Pupa. (1) body stout, rather short; (2) urogomphi short; (3) rostrum moderately slender; (4) setae various in length; (5) head with one os; (6) rostrum with one or two rs; (7) pronotum with two as, without or with one ds, two ls, three pls; (8) meso- and metanotum with two setae; (9) abdominal segments I–VII with two or three setae dorsally and three minute setae ventrally.

The adults of this assemblage of several taxa are mostly very similar to each other, but, lacking synapomorphies, they were treated by Caldara et al. (2013) as a “complex” of species. Overall, they are characterised by small size (length shorter than 2.5 mm), usually with short, oval elytra, and with integument, at least in part, reddish. The larvae also have a combination of characters that distinguish them from those of the other groups, although with no clear autapomorphies. In contrast, the pupae are unique in having abdominal segments I–VII with 2–3 setae dorsally and three minute setae ventrally. Therefore, we can consider these species as an informal group like the other species groups.

7 L3 larvae and 13 pupae, Serbia, Staničenje, 6.07.2017, 43°12.915'N, 22°30.495'E, 364 m., ex Plantago lanceolata, lgt. I. Toševski. Accession numbers of sequenced specimens MN992009 (larva), MN992010 (pupa).

(Figures 1A–D, 2A–F). Measurements (in mm). Body length: 1.60–1.96. Body width (metathorax): 1.00–1.20. Head width: 0.36–0.40.

Body (Figure 1A–D) white, slender, curved. Chaetotaxy of thoracic segments relatively well developed, setae capilliform, different in length, light yellow, on thoracic segments elongated or medium, on abdominal segments very short. Prothorax (Figure 1B) with eight prns of almost equal length, two ps and one eus. Meso- and metathorax (Figure 1B) with one medium prs, three medium pds, equal in length; one medium as, three medium ss, equal in length; one long eps, one long ps and one long eus. Pedal area with five long, equal in length pda. Abdominal segments I–VIII (Figure 1C, D) with one very short prs, four short pds (arranged along the posterior margin), two minute ss, two short eps, one short ps, one short lsts and two short eus. Abdominal segment IX (Figure 1D) with three medium ds, all located close to the posterior margin, one short ps and two short sts. Each of anal lobes with two minute ts.

Figure 1. 

Mecinus pascuorum mature larva, habitus and chaetotaxy A habitus of the body and frontal view of the head B lateral view of thoracic segments C lateral view of abdominal segment I D lateral view of abdominal segments VII–X. Abbreviations: Th. I–III – number of thoracic segments, Abd. I–X – number of abominal segments, setae: as – alar, ds – dorsal, eps – epipleural, eus – eusternal, lsts – laterosternal, pda – pedal, pds – postdorsal, prns – pronotal, prs – prodorsal, ps – pleural, ss – spiracular, sts – sternal, ts – terminal.

Head capsule (Figures 1A, 2A–F) white, almost rounded. Des_{1–3, 5} long, des₄ two times shorter than des₁. Fs₁ as long as des₁, fs_{4, 5} elongated, equal in length. Les₁ medium, les₂ long; both ves very short, and two very short pes (Figure 2A). Antennae (Figure 2B) with conical, elongated sensorium (Se), four times as long as wide, and three sensilla basiconica. Clypeus (Figure 2C) trapezium-shaped, anterior margin slightly concave; cls₂ short; clss close to cls₂. Labrum (Figure 2C) narrow, trapezium-shaped, anterior margin distinctly sinuate; lrs₁ long, lrs₂ and lrs₃ medium. Epipharynx (Figure 2D) with three finger-like als of almost equal length; two finger-like ams, different in length; two short finger-like mes; surface smooth; labral rods very short, rounded. Mandibles (Figure 2E) conical, rather wide, with divided apex (teeth of different lengths, curved); small protuberance in the middle of the cutting edge; with two medium mds capilliform, equal in length, placed transversely. Maxilla (Figure 2F) with one medium stps and two medium pfs; mbs short; mala with six long rod-like dms of almost equal size, five vms different in length. Maxillary palpi: basal palpomere distinctly wider and longer than distal. Prelabium (Figure 2F) cup-like with one long prms; ligula with two short ligs of different length; premental sclerite weakly developed, cup-like. Postlabium (Figure 2F) with short pms₁, long pms₂, and short pms₃.

Figure 2. 

Mecinus pascuorum mature larva, head and mouth parts A head, frontal view B antenna C clypeus and labrum, dorsal view D epipharynx E left mandible F maxillolabial complex, ventral aspect. Abbreviations: at – antenna, clss – clypeal sensorium, des – dorsal epicranial, lr – labral rods, sb – sensillum basiconicum, Se – sensorium, st – stemmata, setae: als – anterolateral, ams – anteromedial, cls – clypeal, dms – dorsal malar, fs – frontal, ligs – ligular, lrs – labral, ls – lateral epicranial, mbs – malar basiventral, mds – mandibular, mes – median, mxps – maxillary palp, pes – postepicranial, ves – ventral, pfs – palpiferal, pms – postlabial, prms – prelabial, stps – stipal, vms – ventral malar.

(Figure 3A–C). Measurements (in mm). Head width: 0.32–0.40. Body width: 0.90–1.20. Body length: 1.52–2.10.

Body moderately stout, slightly curved, white. Rostrum moderately slender, medium long, about 2.5 times as long as wide, reaching mesocoxae. Antennae rather short. Pronotum 1.7 times as wide as long, with two, conical, protuberances apically (p–pr). Urogomorpi (ur) short, conical, with sclerotised apex (Figure 3A–C).

Chaetotaxy well visible, all setae (except those on rostrum and ventral part of abdomen) almost equal in length, medium. Head with one os. Rostrum with one minute rs (Figure 3A). Pronotum with two as placed beside protuberances, two ls, one ds and three pls. Dorsal parts of meso- and metathorax with two setae placed laterally. Abdominal segments I–VIII with three setae situated posteriorly, two elongated setae laterally and three short setae ventrally (median setae distinctly bigger than others). Abdominal segment IX with two micro-setae ventrally.

Figure 3. 

Mecinus pascuorum pupa habitus and chaetotaxy A ventral view B lateral view C dorsal view. Abbreviations: Th. I–III – number of thoracic segments, Abd. I–IX – number of abdominal segments, p–pr – pronotal protuberances, ur – urogomphi, setae: as – apical, d – dorsal, ds – discal, fes – femoral, l, ls – lateral, os – orbital, pls – posterolateral, rs – rostral.

This species lives on Plantago lanceolata L. In spring, the female lays one egg per developing pyxidium, and each larva consumes the contents of a pyxidium, usually two seeds, without causing externally visible modification. Pupation takes place within the same pyxidium. Adults emerge from the beginning of summer until September. They overwinter in the soil (Hoffmann 1958; Scherf 1964; Dickason 1968; Nieminen and Vikberg 2015).

This species is one of the most common species in the genus, with a very large range of distribution: Europe, the Caucasian states, the Middle East, central Asia, and Algeria (Caldara and Fogato 2013). It has been imported to North America, Australia and New Zealand (O’Brien and Wibmer 1982; Debinski and Holt 2000) and recently collected in South Africa (Caldara et al. 2009). Morphologically, this species is more closely related to other species of the group, i.e., M. latiusculus (Jacquelin du Val, 1855) and M. ictericus than to M. labilis studied herein, and this seems also to be corroborated by the preliminary molecular data (I. Toševski, unpublished data). However, the relationships among the immatures of these species are closer than their relationships with all the other species currently known.

3 L3 larvae and 9 pupae, Serbia, Staničenje, 6.07.2017, 43°12.915'N 22°30.495'E, 364 m., ex Plantago lanceolata, lgt. I. Toševski. Accession numbers of sequenced specimen MN992008.

(Figures 4A–D, 5A–F). Measurements (in mm). Body length: 1.40–2.00. Body width (metathorax): 0.84–1.00. Head width: 0.36–0.40.

Body (Figure 4A–D) white, moderately slender, slightly curved. Chaetotaxy of thoracic segments relatively well developed, setae capilliform, different in length, light yellow, on abdominal segments I–VII very short, on segments VIII and IX of medium length. Prothorax (Figure 4B) with eleven long prns of almost equal length, two long ps and one long eus. Meso- and metathorax (Figure 4B) with one short prs, three pds (pds₁ short, pds_2–3 long), one long as, three ss different in length (one minute and two medium), one long eps, one long ps and one long eus. Pedal area with four pda (two long and two medium). Abdominal segments I–VIII (Figure 4C, D) with one short prs, four short pds arranged along posterior margin, two minute ss, two short eps, one short ps, one short lsts and two short eus. Abdominal segment IX (Figure 4D) with three medium ds, all located close to posterior margin, one medium ps and two rather short sts. Each of anal lobes with one minute seta.

Figure 4. 

Mecinus labilis mature larva, habitus and chaetotaxy A habitus of the body and frontal view of the head B lateral view of thoracic segments C lateral view of abdominal segment I D lateral view of abdominal segments VII–X. Abbreviations: Th. I–III – number of thoracic segments, Abd. I–X – number of abominal segments, setae: as – alar, ds – dorsal, eps – epipleural, eus – eusternal, lsts – laterosternal, pda – pedal, pds – postdorsal, prns – pronotal, prs – prodorsal, ps – pleural, ss – spiracular, sts – sternal, ts – terminal.

Head capsule (Figures 4A, 5A–F) white, almost rounded. Des_1–3,5 long, des₄ very short. Fs₁ slightly shorter than des₁, fs₄ and fs₅ equal in length, almost as long as des₁. Les₁ and les₂ long; one ves very short (Figure 5A). Antennae (Figure 5B) with elongated sensorium (Se), four times as long as wide, and two sensilla basiconica and one sensillum ampullaceum. Clypeus (Figure 5C) trapezium-shaped, anterior margin almost straight; cls₂ short, clss placed close to cls₂. Labrum (Figure 5C) narrow, trapezium-shaped, anterior margin distinctly sinuate; lrs₁ long, lrs₂ and lrs₃ medium. Epipharynx (Figure 5D) with three elongated, finger-like als of equal length; two relatively elongated, finger-like ams; two short finger-like mes; surface smooth; labral rods very short, rounded. Mandibles (Figure 5E) conical, rather wide, with divided apex; both mds capilliform, short, equal in length, placed transversely. Maxilla (Figure 5F) with one medium stps and two medium pfs; mbs short; mala with six long rod-like dms of almost equal size, five vms different in length. Maxillary palpi: basal palpomere distinctly wider than distal. Prelabium (Figure 5F) cup-like with one short prms; ligula with one minute lig; premental sclerite weakly developed, cup-like. Postlabium (Figure 5F) with very short pms₁, long pms₂, and very short pms₃.

Figure 5. 

Mecinus labilis mature larva, head and mouth parts A head, frontal view B antenna C clypeus and labrum, dorsal view D epipharynx E left mandible F maxillolabial complex, ventral aspect. Abbreviations: at – antenna, clss – clypeal sensorium, des – dorsal epicranial, lr – labral rods, sa – sensillum ampullaceum, sb – sensillum basiconicum, Se – sensorium, st – stemmata, setae: als – anterolateral, ams – anteromedial, cls – clypeal, dms – dorsal malar, fs – frontal, ligs – ligular, lrs – labral, ls – lateral epicranial, mbs – malar basiventral, mds – mandibular, mes – median, mxps – maxillary palp, pes – postepicranial, ves – ventral, pfs – palpiferal, pms – postlabial, prms – prelabial, stps – stipal, vms – ventral malar.

(Figure 6A–C). Measurements (in mm). Head width: 0.36–0.40. Body width: 1.00–1.40. Body length: 1.40–2.20.

Body rather stout, slightly curved, white. Rostrum slender, moderately short, about 2.0 times as long as wide, reaching procoxae. Antennae short. Pronotum 2.2 times as wide as long. Urogomorpi (ur) very short, conical, only slightly reaching outline of the body (Figure 6A–C).

Chaetotaxy almost invisible, all setae minute, possible to observation only under higher magnification. Head with one os. Rostrum with two rs placed medially (Figure 6A). Pronotum with two as, two ls, one ds and three pls. Dorsal parts of meso- and metathorax with two setae placed laterally. Abdominal segments I–VIII with three setae situated posterolaterally, two setae laterally and three setae ventrally. Abdominal segment IX with two micro-setae ventrally.

Figure 6. 

Mecinus labilis pupa habitus and chaetotaxy A ventral view B lateral view C dorsal view. Abbreviations: Th. I–III – number of thoracic segments, Abd. I–IX – number of abdominal segments, ur – urogomphi, setae: as – apical, d – dorsal, ds – discal, fes – femoral, l, ls – lateral, os – orbital, pls – posterolateral, rs – rostral, sls – superlateral.

Larvae feed on Plantago lanceolata L. in galled pyxidia, where they pupate in the collar without causing externally visible modifications (Hoffmann 1958).

This species is widely distributed in Europe, the Caucasian states, and Turkey. Concerning the adults, the pattern of the elytral integument (reddish with two black oblique bands from interstria 1 to 7) and the shape of the rostrum (in lateral view moderately curved in basal half then straight to apex) allow us to separate these two species from all the others. With regard to the immatures, the differences from the other studied species of the group, M. pascuorum, are several and are reported in the key. Molecular data also do not show a close relationship between these two species (I. Toševski, unpublished data).

Larva. (1) cuticle of the body smooth; (2) pedal lobes prominent; (3) abdominal segment X reduced to three anal lobes of equal size; (4) thoracic spiracle unicameral; (5) all abdominal setae short or very short, without trend to become progressively longer from abd. segment I to VIII; (6) abdominal segments I–VIII with three pds and two ss; (7) head white, rounded; (8) frontal suture poorly developed; (9) endocarina 3/4 of the frons; (10) des₄ three times shorter than des₁; (11) absence of fs₁; (12) absence of fs₂; (13) fs₃ three times shorter than fs₄; (14) head with one stemma; (15) absence of cls₁; (16) labial palpi one-segmented; (17) premental sclerite cup-like, posterior extension with elongated, acute apex; (18) surface of postlabium smooth.

Pupa. (1) body stout and short; (2) urogomphi extremely short, not reaching outline of the body; (3) rostrum short, tapering to the top; (4) setae minute, almost invisible; (5) head with one os; (6) rostrum with one rs; (7) pronotum with two as, one ds, one ls, three pls; (8) meso- and metanotum with two setae; (9) abdominal segments I–VII with three setae dorsally and without setae ventrally.

The very short, conical and in lateral view straight rostrum, and the protibiae with apical third distinctly enlarged, sometimes with outer margin and apex bearing stout denticles, are truly noteworthy and unique in Mecinini. Both characters are oddly similar to those of a mole, and the tibiae are similar to those of Scarabaeidae. Since nothing was known about their biology except for their host plants, Caldara and Fogato (2013) speculated on the possibility that the species of this group deposit eggs in plant roots. The new biological data on M. pirazzolii below reported exclude this hypothesis and suggest that most likely the female is able to approach as close as possible to the pistil of the flower and deposit the egg thanks to the shape of its protibiae, since it is regularly found deeply stuck between Plantago inflorescences. This group might be related to the M. collaris group on the basis of the morphological characters of the adults (Caldara et al. 2013), whereas it seems more related to the M. circulatus group according to the preliminary molecular data (I. Toševski, unpublished data). Unfortunately, the study of immatures did not clarify this situation. In fact, the presence of one palpomere on the labial palpi and of all spiracles unicameral contradicts this hypothesis, and the same combination of these two characters is found only in M. pascuorum and M. heydenii groups, with the former of which the M. simus group might have major similarities. However, the immatures of the M. simus group have some autapomorphies, such as a smooth body cuticle and prominent pedal lobes in larvae and abdominal segments I–VII with three setae dorsally and without setae ventrally, apart from an obvious extraordinarily short rostrum tapering to the apex in pupae.

20 L3 larvae and 10 pupae, Serbia, Veliko Gradište, 14.07.2017, 44°45.039'N, 21°31.426'E, 86 m., ex Plantago arenaria, lgt. I. Toševski. Accession numbers of sequenced specimens MN992011 (larva), MN992012 (pupa).

(Figures 7A–D, 8A–F). Measurements (in mm). Body length: 1.40–2.00. Body width (metathorax): 0.73–1.00. Head width: 0.36–0.40.

Body (Figure 7A–D) white, slender, curved. Chaetotaxy of thoracic segments relatively well developed, setae capilliform, different in length, light yellow; on abdominal segments almost invisible (except dorsal parts of abdominal segments IX and X). Prothorax (Figure 7B) with eight prns of unequal length (seven relatively long and one medium), two relatively long ps and one short eus. Meso- and metathorax (Figure 7B) with one medium prs, two long pds, equal in length, one long as, three ss different in length (two relatively long, one short), one long eps, one long ps and one short eus. Pedal area with five long pda, equal in length. Abdominal segments I–VIII (Figure 7C, D) with one very short prs, three short pds (on segment VIII medium, equal in length), arranged along posterior margin, two minutess, one short eps, one short ps, one short lsts and two short eus. Abdominal segment IX (Figure 7D) with three medium ds, all located close to posterior margin, one short ps and two short sts. Each of anal lobes with one minute seta.

Figure 7. 

Mecinus pirazzolii mature larva, habitus and chaetotaxy A habitus of the body and frontal view of the head B lateral view of thoracic segments C lateral view of abdominal segment I D lateral view of abdominal segments VII–X. Abbreviations: Th. I–III – number of thoracic segments, Abd. I–X – number of abominal segments, setae: as – alar, ds – dorsal, eps – epipleural, eus – eusternal, lsts – laterosternal, pda – pedal, pds – postdorsal, prns – pronotal, prs – prodorsal, ps – pleural, ss – spiracular, sts – sternal, ts – terminal.

Head capsule (Figures 7A, 8A–C) light white, almost rounded. Des_1,3,5 long; des₂ two times shorter than des₁; des₄ three times shorter than des₁. Fs_4,5 equal in length, almost as long as des₁. Les₁ medium, les₂ long; one very short ves, and one pes (Figure 8A). Antennae (Figure 8B) with conical, elongated sensorium (Se), four times as long as wide, and three sensilla basiconica. Clypeus (Figure 8C) trapezium-shaped, anterior margin slightly concave; cls₂ short; clss situated close to cls₂. Labrum (Figure 8C) narrow, trapezium-shaped, anterior margin slightly sinuate; lrs₁ long, lrs₂ medium lrs₃ short. Epipharynx (Figure 8D) with three finger-like als of almost equal length; two medium finger-like ams; two short finger-like mes; surface smooth; labral rods very short, rounded. Mandibles (Figure 8E) conical, rather wide, with a small protuberance in the middle of the cutting edge; both mds capilliform, medium, equal in length, placed transversely. Maxilla (Figure 8F) with one stps and two pfs of equal length; mbs short; mala with six long rod-like dms of almost equal size, five vms different in length. Maxillary palpi: basal palpomere distinctly wider and longer than distal. Prelabium (Figure 8F) cup-like with one long prms; ligula with two short ligs; premental sclerite clearly visible, cup-shaped, posterior extension with acute apex. Postlabium (Figure 8F) with medium pms₁, medium pms₂, and short pms₃.

Figure 8. 

Mecinus pirazzolii mature larva, head and mouth parts A head, frontal view B antenna C clypeus and labrum, dorsal view D epipharynx E left mandible F maxillolabial complex, ventral aspect. Abbreviations: at – antenna, des – dorsal epicranial, lr – labral rods, sb – sensillum basiconicum, Se – sensorium, st – stemmata, setae: als – anterolateral, ams – anteromedial, cls – clypeal, dms – dorsal malar, fs – frontal, ligs – ligular, lrs – labral, ls – lateral epicranial, mbs – malar basiventral, mds – mandibular, mes – median, mxps – maxillary palp, pes – postepicranial, ves – ventral, pfs – palpiferal, pms – postlabial, prms – prelabial, stps – stipal, vms – ventral malar.

(Figure 9A–C). Measurements (in mm). Head width: 0.33–0.40. Body width: 0.93–1.16. Body length: 1.63–2.10.

Body stout, slightly curved, white. Rostrum slender, very short, tapering to its top. Antennae moderately elongated. Pronotum 2.0 times as wide as long. Urogomorpi (ur) very short, conical, not reaching outline of the body (Figure 9A–C).

Chaetotaxy almost invisible, all setae minute, possible to observation only under higher magnification. Head with one os. Rostrum with one rs placed medially (Figure 9B). Pronotum with two as, one ls, one ds and three pls. Dorsal parts of meso- and metathorax with two setae placed laterally. Dorsal parts of abdominal segments I–VIII with three setae situated posterolaterally and one seta laterally. Abdominal segment IX without setae.

Figure 9. 

Mecinus pirazzolii pupa habitus and chaetotaxy A ventral view B lateral view C dorsal view. Abbreviations: Th. I–III – number of thoracic segments, Abd. I–IX – number of abdominal segments, ur – urogomphi, setae: as – apical, d – dorsal, ds – discal, fes – femoral, l, ls – lateral, os – orbital, pls – posterolateral, rs – rostral.

This species is associated with the annual plant Plantago arenaria Waldst. & Kit. The adult aggregation on plants is followed by the appearance of flowering stems with spikes in late spring. The females lay one egg onto the base of the pistil or the initialised seed. The act of oviposition is followed by proliferative growth of the ovarian tissue in the form of gall but without changes in the external morphology of the pyxidium. During development, the larvae consume all the tissue inside the pyxidium, leaving only the fruit shell intact. The larvae pupate inside the fruit shell, from which adults emerge after being completely sclerotised. Overwintering takes place in the soil litter near the host plant (I. Toševski, pers. obs.). Sympatric occurrence with M. ictericus is common (Caldara and Fogato 2013).

This species is distributed in eastern Central Europe, southeastern Europe and Turkey. In our keys, this species is closer to the species of the M. pascuorum group than to others, as already discussed in the Remarks for the group.

Larva. (1) body covered with asperities; (2) pedal lobes prominent well isolated; (3) abdominal segment X reduced to three anal lobes of unequal size; (4) thoracic spiracle bicameral; (5) abdominal setae very short, slightly growing from abdominal segment I to VIII; (6) abdominal segments I–VIII with three pds and two ss; (7) head brown, distinctly flattened laterally; (8) frontal suture poorly or well visible; (9) endocarina 1/2 of the frons; (10) des₄ very short or short; (11) presence of fs₁; (12) absence of fs₂; (13) fs₃ very short; (14) head with two stemmata; (15) presence of cls₁; (16) labial palpi one-segmented; (17) premental sclerite cup-like; (18) surface of postlabium smooth.

Pupa. (1) body elongated or very elongated; (2) urogomphi slender, short or medium, reaching outline of the body, directed downward; (3) rostrum moderately elongated; (4) setae minute or medium; (5) head with one vs, one or two sos, one or two os; (6) rostrum with one sls and one rs; (7) pronotum with one or two as, without or with one ds, two sls, without or up to two ls, two or three pls; (8) meso- and metanotum with two setae; (9) abdominal segments I–VII with three or five setae dorsally.

The adults of this group are characterised by body elongate, subcylindrical, elytral integument reddish and black to completely black, protibiae with apical part of ventral surface distinctly directed outward. On the basis of these characters, this group might be related to M. collaris and especially to the M. simus group (Caldara et al. 2013). The study of the immatures does not support this latter relationship. The immatures of this group lack autapomorphies. However, the larvae possess the unique combination of one palpomere + thoracic spiracle bicameral and abdominal spiracles unicameral, which do not share with the species of the M. simus group, M. pirazzolii, that we have studied.

5 L3 larvae and 10 pupae, 1.07.2017, Zemun, Serbia, GPS 44°39.030'N, 21°28.355'E, 162 m., lgt. I. Toševski. Accession number of sequenced specimen MN991999.

(Figures 10A–D, 11A–F). Measurements (in mm). Body length: 2.33–2.73. Body width (metathorax): 0.83–1.06. Head width: 0.50–0.53.

Body (Figure 10A–D), light yellow, slender, curved (Figure 10B). Thoracic segments larger than abdominal segment I. Abdominal segments I–VI of almost equal length; segments VII–IX decreasing gradually to the terminal body part; segment X reduced to three anal lobes of those lateral are the largest, and dorsal the smallest (sometimes absent). Chaetotaxy weakly developed, setae short, transparent, difficult to observe (Figure 10B). Prothorax (Figure 10B) with eight prns (six medium and two very short); two medium ps and one very short eus. Meso- and metathorax (Figure 10B) with one very short prs, two pds (one very short, one medium), one medium as, three ss (two medium and one very short), one medium eps, one medium ps and one very short eus. Pedal area with three pda (one medium and two very short). Abdominal segments I–VIII (Figure 10C, D) with one very short prs, three pds arranged along the posterior margin (order: very short, medium and very short), two ss different in length, two eps different in length, one medium ps, one medium lsts and two very short eus. Abdominal segment IX (Figure 10D) with two ds (one medium and one very short), all located close to the posterior margin, one very short ps and two very short sts. Each lateral anal lobe (abd. seg. X) with one minute seta.

Figure 10. 

Mecinus circulatus mature larva, habitus and chaetotaxy A habitus of the body and frontal view of the head B lateral view of thoracic segments C lateral view of abdominal segment I D lateral view of abdominal segments VII–X. Abbreviations: Th. I–III – number of thoracic segments, Abd. I–X – number of abominal segments, setae: as – alar, ds – dorsal, eps – epipleural, eus – eusternal, lsts – laterosternal, pda – pedal, pds – postdorsal, prns – pronotal, prs – prodorsal, ps – pleural, ss – spiracular, sts – sternal, ts – terminal.

Head capsule (Figures 10A, 11A–F) pale brown, narrowed bilaterally. Frontal suture poorly visible. Des_1–3 very long, equal in length, des₄ four times shorter than des₁, des₅ slightly shorter than des₁. Fs₁ short; fs₃ short, fs_4,5 long. Les₁ and les₂ equal in length, slightly shorter than des₁; both ves short, and five short pes (Figure 11A). Antennae (Figure 11B) with conical sensorium (Se) four times as long as wide, and three sensilla basiconica. Clypeus (Figure 11C) trapezium-shaped, anterior margin concave; cls_1-2 relatively short; clss placed close to cls₂. Labrum (Figure 11C) with distinctly sinuate anterior margin; lrs₁ very long, lrs₂ slightly shorter than lrs₁, lrs₃ two times shorter than lrs₁. Epipharynx (Figure 11D) with three medium, finger-shaped als of almost equal length; two rod-like ams, equal in length; one finger-like mes of medium length; surface smooth; labral rods close to kidney-shaped. Mandibles (Figure 11E) conical, wide, with a small protuberance in the middle of the cutting edge; both mds capilliform, medium, equal in length, placed mediolaterally. Maxilla (Figure 11F) with one stps and two pfs equal length; mbs very short; mala with six finger-like dms of almost equal size; four vms different in length. Maxillary palpi: basal palpomere distinctly wider and slightly longer than distal. Prelabium (Figure 11F) cup-like with one relatively short prms; ligula with two ligs different in length; premental sclerite well visible, cup-shaped. Postlabium (Figure 11F) with medium pms₁, long pms₂, and medium pms₃.

Figure 11. 

Mecinus circulatus mature larva, head and mouth parts A head, frontal view B antenna C clypeus and labrum, dorsal view D epipharynx E left mandible F maxillolabial complex, ventral aspect. Abbreviations: at – antenna, clss – clypeal sensorium, lr – labral rods, sb – sensillum basiconicum, Se – sensorium, st – stemmata, setae: als – anterolateral, ams – anteromedial, cls – clypeal, des – dorsal epicranial, dms – dorsal malar, fs – frontal, ligs – ligular, lrs – labral, ls – lateral epicranial, mbs – malar basiventral, mds – mandibular, mes – median, mxps – maxillary palp, pes – postepicranial, ves – ventral, pfs – palpiferal, pms – postlabial, prms – prelabial, stps – stipal, vms – ventral malar.

(Figure 12A–C). Measurements (in mm). Head width: 0.46–0.50. Body width: 1.16–1.40. Body length: 2.46–3.00.

Body moderately elongated, white. Rostrum rather short, about 3.2 times as long as wide, reaching up to mesocoxae. Antennae slender and elongated. Pronotum 1.25 times as wide as long. Mesonotum slightly shorter than metanotum. Urogomphi (ur) short, slender, conical, with sclerotised, sharp apex, slightly reaching outline of the body, directed downward (Figure 12A–C).

Chaetotaxy very sparse, setae short or minute. Head with one vs, one os and one sos. Rostrum with one rs and one pas. Setae on head and rostrum straight, as long as those on prothorax (Figure 12A). Pronotum with one as, one ls, two sls, and two pls. Dorsal parts of meso- and metathorax with two setae placed medially. Apex of femora with one minute fes (Figure 12A–C). Dorsal parts of each abdominal segments I–VIII with three setae placed posteromedially along margins of each segments. Abdominal segment IX with two micro-setae ventrally.

Figure 12. 

Mecinus circulatus pupa habitus and chaetotaxy A ventral view B lateral view C dorsal view. Abbreviations: Th. I–III – number of thoracic segments, Abd. I–IX – number of abdominal segments, ur – urogomphi, setae: as – apical, d – dorsal, fes – femoral, l, ls – lateral, os – orbital, sls – postantennal, pls – posterolateral, rs – rostral, sls – superlateral, sos – superorbital, vs – vertical.

This species is very common on Plantago lanceolata L., while in southeastern Europe, it is also common on some other closely related species, such as P. arenaria (sub P. psyllium L.), P. afra L. (sub P. cynops L.) and P. subulata L. (Hoffmann 1958; Sprick 2001). The females oviposit in early spring on young growing vegetative shoot buds. Newly hatched larvae bore through the central part of the shoot bud, forming a 1–2 cm long larval channel that rarely rises above the root crown. The larvae pupate inside the larval channel, and the emerged adult leaves the pupa chamber after a short time. The adult overwinters in the soil litter near the host plant.

This is a common species in western, central and southern Europe, northern Africa and the Middle East. By the colour of the elytral integument, with black and reddish vittae, the adults differ from M. pyraster, whose integument is completely black. However, both the study of the morphological characters in adults and immatures and the preliminary molecular study (I. Toševski, unpublished data) agree with the hypothesis of close relationships between these two species.

Larvae are easily separable from those of M. pyraster: the pronotum has eight prns instead of 11, the pedal lobes has three pda instead of five, the anal lobes with one ts instead of two, the head with five pes instead of four, the mandible with two mds instead of one, the mala with four vms instead of five, and the prms are shorter.

Pupae differ from those of M. pyraster by the head with one sos and one os instead of two, the pronotum with a different number of setae in all positions, and the abdominal segments I–VII with three setae dorsally instead of five.

4 L3 larvae and 5 pupae, Serbia, Zemun, 1.07.2017, GPS 44°39.030'N, 21°28.355'E, 162 m., ex l., ex Plantago lanceolata, lgt. I. Toševski. Accession number of sequenced specimen MN992000.

(Figures 13A–D, 14A–F). Measurements (in mm). Body length: 2.00–2.83. Body width (metathorax or abdominal segments I–II): 0.83–1.00. Head width: 0.53–0.56.

Body (Figure 13A–D) yellowish, slender, curved, densely covered with asperities. Metathorax as large as abdominal segment I. Abdominal segments I–VI of almost equal length, abdominal segments VII–IX decreasing gradually to the terminal body part, segment X reduced to three anal lobes of those lateral are the largest, and dorsal the smallest (sometimes absent). Chaetotaxy weakly developed, setae short or medium. Prothorax (Figure 13B) with eleven prns (eight medium and three very short); two medium ps and one very short eus. Meso- and metathorax (Figure 13B) with one very short prs, two very short pds, one very short as, three ss (two medium and one very short), one medium eps, one medium ps and one very short eus. Pedal area with five pda (three medium and two very short). Abdominal segments I–VIII (Figure 13C, D) with one very short prs, three very short pds arranged along the posterior margin, two very short ss, two eps different in length, one medium ps, one medium lsts and two very short eus. Abdominal segment IX (Figure 13D) with three ds (one medium and two very short), all located close to the posterior margin, one medium ps and two very short sts. Each lateral anal lobe with two minute setae.

Figure 13. 

Mecinus pyraster mature larva, habitus and chaetotaxy A habitus of the body and frontal view of the head B lateral view of thoracic segments C lateral view of abdominal segment I D lateral view of abdominal segments VII–X. Abbreviations: Th. I–III – number of thoracic segments, Abd. I–X – number of abominal segments, setae: as – alar, ds – dorsal, eps – epipleural, eus – eusternal, lsts – laterosternal, pda – pedal, pds – postdorsal, prns – pronotal, prs – prodorsal, ps – pleural, ss – spiracular, sts – sternal, ts – terminal.

Head capsule (Figures 13A, 14A–F) dark brown, narrowed bilaterally. Frontal suture visible. Des_1–3,5 very long, equal in length; des₄ three times shorter than des₁. Fs_1,4,5 long; fs₃ very short. Les₁ and les₂ equal in length, slightly shorter than des₁; ves_1–2 short; pes_1–2 short (Figure 14A). Antennae (Figure 14B) with sensorium (Se) slender, four times as long as wide, and three sensilla basiconica. Clypeus (Figure 14C) trapezium-shaped, anterior margin distinctly sinuated; both cls relatively long, clss absent. Labrum (Figure 14C) with slightly sinuate anterior margin; lrs₁ long, lrs₂ and lrs₃ medium. Epipharynx (Figure 14D) with three medium, finger-shaped als of almost equal length; two rod-like ams different in length; two finger-like mes of medium length; surface smooth; labral rods close to kidney-shaped. Mandibles (Figure 14E) conical, wide, with small protuberance in the middle of the cutting edge; one capilliform mds, medium, placed mediolaterally. Maxilla (Figure 14F) with one stps and two pfs equal in length; mbs very short; mala with six finger-like dms of different size (dms_1–2 medium, dms_3–6 long to very long), five vms different in length. Maxillary palpi: basal palpomere slightly wider than distal, both palpomeres almost equal in length. Prelabium (Figure 14F) cup-like with one relatively long prms; ligula with two ligs different in length; premental sclerite well visible, cup-shaped. Labial palpi elongated, one-segmented. Postlabium (Figure 14F) with medium pms₁, long pms₂, and medium pms₃.

Figure 14. 

Mecinus pyraster mature larva, head and mouth parts A head, frontal view B antenna C clypeus and labrum, dorsal view D epipharynx E left mandible F maxillolabial complex, ventral aspect. Abbreviations: at – antenna, lr – labral rods, sb – sensillum basiconicum, Se – sensorium, st – stemmata, setae: als – anterolateral, ams – anteromedial, cls– clypeal, des – dorsal epicranial, dms – dorsal malar, fs – frontal, ligs – ligular, lrs – labral, ls – lateral epicranial, mbs – malar basiventral, mds – mandibular, mes – median, mxps – maxillary palp, pes – postepicranial, ves – ventral, pfs – palpiferal, pms – postlabial, prms – prelabial, stps – stipal, vms – ventral malar.

(Figure 15A–C). Measurements (in mm). Head width: 0.53–0.63. Body width: 1.40–1.73. Body length: 3.33–4.26.

Figure 15. 

Mecinus pyraster pupa habitus and chaetotaxy A ventral view B lateral view C dorsal view. Abbreviations: Th. I–III – number of thoracic segments, Abd. I–IX – number of abdominal segments, ur – urogomphi, setae: as – apical, d – dorsal, ds – discal, fes – femoral, l, ls – lateral, os – orbital, sls – postantennal, pls – posterolateral, rs – rostral, sls – superlateral, sos – superorbital, vs – vertical.

Body elongated, white. Rostrum rather slender, about three times as long as wide, reaching almost up to mesocoxae. Antennae slender and elongated. Pronotum 1.8 times as wide as long. Urogomphi (ur) slender and rather elongated, conical, with sclerotised apex, reaching outline of the body, directed downward (Figure 14A–C).

Chaetotaxy well developed, setae rather short. Head capsule with one vs, two sos equal in length, two os equal in length. Rostrum with one rs and one sls (Figure 14A). Pronotum with two as, one ds, two sls, two ls, and three pls (Figure 14A–C); equal in length (Figure 14B). Setae on head and rostrum as long as those on prothorax. Dorsal parts of meso- and metathorax with two setae different in length placed medially. Abdominal segments I–VIII with two medium setae laterally and three medium setae ventrally, distributed in regular lines. Dorsal parts of abdominal segments I–VII with five setae (d₁ placed anteromedially, d_2–4 posteromedially and d₅ located posterolaterally); abdominal segment VIII with only four very long setae dorsally. Abdominal segment IX with two micro-setae ventrally.

This species is associated with some Plantago species (P. lanceolata L., P. lagopus L., P. media L.) (Hoffmann 1958; Sprick 2001). In west Palearctic larvae are most frequently found in the roots of P. lanceolata, boring channels in upper part of the root crown. Larger roots may inhabit several larvae. Pupation takes place during early summer in the pupal chamber situated in the upper part of larval channel. After emergence, adults overwinter in the soil litter nearby host plant.

This species is very common and widespread in the Palearctic region. It was also reported in North America (O’Brien and Wibmer 1982). The adult is distinctly variable in the size and shape of the body and vestiture within the same population. It differs from M. circulatus by the black integument and ventrite 5 in the male bearing a median tuft of hair. In larvae, the pronotum has eleven prns instead of eight, the pedal lobes have five pda instead of three, the anal lobes with two ts instead of one, the head with four pes instead of five, the mandible with one mds instead of two, the mala with five vms instead of four, and the prms are longer. The pupae also differ from those of M. circulatus by a different number of setae on head, pronotum and abdominal segments I–VII (see key to the pupae). However, morphological and molecular studies (I. Toševski, unpublished data) demonstrate a clear relationship between M. pyraster and M. circulatus.

Larva. (1) slightly pressed dorso-ventrally, cuticle densely tuberculate, premental sclerite, pedal lobes and spiracular area of meso- and metathorax dark pigmented; (2) pedal lobes prominent well isolated; (3) abdominal segment X reduced to three anal lobes of equal size; (4) thoracic spiracle bicameral; (5) abdominal setae short; (6) abdominal segments I–VII with four pds and two ss (abd. segment VIII with one ss); (7) head brown, flattened laterally; (8) frontal suture visible; (9) endocarina 1/2 of the frons; (10) des₄ minute or short; (11) presence of fs₁; (12) absence of fs₂; (13) fs₃ minute; (14) head with one stemma; (15) presence of cls₁; (16) labial palpi two-segmented; (17) premental sclerite cup-like; (18) surface of postlabium smooth.

Pupa. (1) body elongated; (2) urogomphi slender, rather short, reaching outline of the body, directed downward; (3) rostrum moderately elongated; (4) setae different in length; (5) head with one sos; (6) rostrum with one rs; (7) pronotum with two as, one ds, one sls, one ls, four pls; (8) meso- and metanotum with two setae; (9) abdominal segments I–IV without setae dorsally; segments V–VII dorsally with five growing setae.

The adults of this monobasic group are easily distinguishable from all other species of Mecinus by several autapomorphies, such as rostrum short and wide, straight in lateral view, scrobe not reaching anterior margin of eye, elytra elongate, broad scales densely covering base of pronotum, epimera and episterna. In contrast, immatures have few autapomorphies, i.e., larvae are slightly pressed dorsoventrally, with a densely tuberculate cuticle, whereas premental sclerite, pedal lobes and spiracular area of meso- and metathorax are dark pigmented; the pupae have abdominal segments I–IV lacking setae dorsally, whereas segments V–VII dorsally possess five growing setae.

Presently, it is unclear to which species M. collaris is more closely related. The other species with short and straight rostrum, such as those of the M. simus group, do not apparently share other synapomorphies with M. collaris. In contrast, the larvae of the latter share the number of palpomeres of the labial palpi (two) and the shape of the thoracic spiracle (bicameral) and abdominal spiracles (unicameral) with the M. janthinus group. The pupae of M. collaris differ from all the others studied here by the dorsal setae of the abdominal segments because segments I–IV are without setae and segments V–VII have setae growing gradually.

26 L3 larvae and 21 pupae, Serbia, Zavojskojezero, Pirot, 15.07.2017, GPS 43°12.508'N, 22°35.590'E, 675 m., ex Plantago media, lgt. I. Toševski. Accession numbers of sequenced specimen MN992001.

(Figures 16A–D, 17A–F). Measurements (in mm). Body length: 2.00–3.66. Body width (metathorax): 0.80–1.16. Head width: 0.56–0.66.

Body (Figure 16A–D) light yellow, slender, curved, slightly pressed dorso-ventrally. Premental sclerite, pedal lobes and spiracular area of meso- and metathorax dark pigmented. Chaetotaxy of thoracic segments relatively well developed, setae capilliform, variable in length, light yellow, on thoracic segments medium or relatively long, on abdominal segments I–IX short or medium. Prothorax (Figure 16B) with eleven prns (six long and one short placed on premental sclerite), next three close to spiracle; two medium ps and one short eus. Meso- and metathorax (Figure 16B) with one medium prs, three medium pds of equal length, one medium as, three medium ss, equal in length, one long eps, one long ps and one short eus. Pedal area with three pda, long or medium. Abdominal segments I–VIII (Figure 16C, D) with one short prs, four short pds arranged along the posterior margin, two minutess, one short eps, one short ps, one short lsts and two short eus. Abdominal segment IX (Figure 16D) with three short ds, all located close to posterior margin, one short ps and two rather short sts. Anal lobes without setae.

Figure 16. 

Mecinus collaris mature larva, habitus and chaetotaxy A habitus of the body and frontal view of the head B lateral view of thoracic segments C lateral view of abdominal segment I D lateral view of abdominal segments VII–X. Abbreviations: Th. I–III – number of thoracic segments, Abd. I–X – number of abominal segments, setae: as – alar, ds – dorsal, eps – epipleural, eus – eusternal, lsts – laterosternal, pda – pedal, pds – postdorsal, prns – pronotal, prs – prodorsal, ps – pleural, ss – spiracular, sts – sternal, ts – terminal.

Head capsule (Figures 16A, 17A–C) dark brown, slightly narrowed bilaterally. Des_1–3,5 long, des₄ short; des₄ located in the central part of epicranium. Fs₁ long, fs₃ very short, fs_4,5 equal in length, almost as long as des₁. Les₁ and les₂ slightly shorter than des₁; two ves, and four pes very short (Figure 17A). Antennae (Figure 17B) with conical, elongated sensorium (Se), three times as long as wide, and two sensilla basiconica and two sensilla ampullacea. Clypeus (Figure 17C) trapezium-shaped, anterior margin almost straight; cls_1-2 medium, equal in length; clss well visible. Labrum (Figure 17C) narrow, trapezium-shaped, anterior margin distinctly sinuate; lrs₁ long, lrs₂ and lrs₃ medium. Epipharynx (Figure 17D) with three elongated, finger-like als of equal length; two medium, straight ams; two short finger-like mes; surface smooth; labral rods very short, close to kidney-shaped. Mandibles (Figure 17E) conical, rather wide; both mds capilliform, medium, equal in length, placed transversely. Maxilla (Figure 17F) with one stps and two pfs of equal length; mbs short; mala with six long rod-like dms of almost equal size, five vms various in length. Maxillary palpi: basal palpomere distinctly wider and slightly shorter than distal. Prelabium (Figure 17F) cup-like with one long prms; ligula with two minute ligs, premental sclerite well developed, with elongated median part. Labial palpi two-segmented; basal palpomere wider and shorter than distal. Postlabium (Figure 17F) with short pms₁, long pms₂, and short pms₃.

Figure 17. 

Mecinus collaris mature larva, head and mouth parts A head, frontal view B antenna C clypeus and labrum, dorsal view D epipharynx E left mandible F maxillolabial complex, ventral aspect. Abbreviations: at – antenna, clss – clypeal sensorium, des – dorsal epicranial, lr – labral rods, sa – sensillum ampullaceum, sb – sensillum basiconicum, Se – sensorium, st – stemmata, setae: als – anterolateral, ams – anteromedial, cls – clypeal, dms – dorsal malar, fs – frontal, ligs – ligular, lrs – labral, ls – lateral epicranial, mbs – malar basiventral, mds – mandibular, mes – median, mxps – maxillary palp, pes – postepicranial, ves – ventral, pfs – palpiferal, pms – postlabial, prms – prelabial, stps – stipal, vms – ventral malar.

(Figure 18A–C). Measurements (in mm). Head width: 0.30–0.36. Body width: 0.76–1.20. Body length: 1.66–2.33.

Body moderately elongated, light yellowish. Rostrum moderately stout, about 2.1 times as long as wide, reaching up to mesocoxae. Antennae relatively short. Pronotum 1.6 times as wide as long. Mesonotum distinctly shorter than metanotum. Urogomphi (ur) short, conical, with sclerotised, sharp apex, slightly reaching outline of the body, directed downward (Figure 18A–C).

Chaetotaxy sparse, setae short, unequal length. Head with only one sos. Rostrum with one rs. Setae on head and rostrum straight, much shorter than those on prothorax (Figure 18A). Pronotum with two as, one sls, one ls, one ds and four pls. Dorsal parts of meso- and metathorax with two setae placed medially. Dorsal parts of abdominal segments I–IV without setae; segments V–VII with five setae (d₁ placed anteromedially, d_2–4 posteromedially, d₅ posterolaterally, under spiracle); segment VIII with four setae dorsally. Abdominal segments I–VIII with four long setae ventrally, distributed in regular lines. Abdominal segment IX with two micro-setae ventrally, and next two on urogomphi.

Figure 18. 

Mecinus collaris pupa habitus and chaetotaxy A ventral view B lateral view C dorsal view. Abbreviations: Th. I–III – number of thoracic segments, Abd. I–IX – number of abdominal segments, ur – urogomphi, setae: as – apical, d – dorsal, ds – discal, fes – femoral, l, ls – lateral, pls – posterolateral, rs – rostral, sls – superlateral, sos – superorbital.

Larvae feed on various species of Plantago, but mainly on P. media L. and P. maritima L. Plantago lanceolata, P. coronopus L., and P. major L. are also known as host plants. The adults are active from mid-spring following the growth of the flowering stems of the host plant. The female oviposits inside the upper parts of the flowering stem that are covered with floral spikes, which induces clearly visible oblong galls. Very often, several larvae develop in a single flowering shoot. The larvae pupate inside the galls and the adults emerge during summer. Overwintering takes place in the soil litter near the host plant.

This species, which is widely distributed in the Palearctic region except in North Africa (Alonso-Zarazaga et al. 2017), is unique in Mecinus, being characterised by long elytra and whitish to orange, wide scales covering the base of the pronotum, the epimera and the episterna. For the differences from the immatures of the other species, see the remarks for the group.

Larva. (1) body densely covered with asperities; (2) pedal lobes weakly isolated; (3) abdominal segment X reduced to three anal lobes of unequal size; (4) thoracic spiracle bicameral; (5) abdominal setae medium to very long, distinclty growing from abdominal segment I to VIII; (6) abdominal segments I–VIII with four pds and usually three ss; (7) head brown, flattened laterally; (8) frontal suture distinct; (9) endocarina 4/5 of the frons; (10) des₄ usually shorter than des₁; (11) presence of fs₁; (12) absence of fs₂; (13) fs₃ as long as half of fs₄; (14) head with two stemmata; (15) presence of cls₁; (16) labial palpi two-segmented; (17) premental sclerite cup-like; (18) surface of postlabium densely covered with asperities.

Pupa. (1) body very slender and elongated; (2) urogomphi rather elongated, distinctly reaching outline of the body, directed outside; (3) rostrum elongated and slender; (4) setae more or less elongated; (5) head with one vs, two sos, two os; (6) rostrum with one or two sls and without or with one rs; (7) pronotum with two as, one ds, two sls, two ls, three or four pls; (8) meso- and metanotum with two or three setae; (9) abdominal segments I–VII dorsally with six or seven elongated, growing setae.

The adult of this species is characterised by elytra distinctly elongate, dorsal integument black or blue, sometimes with metallic reflections.

The shape of the body together with the colour of the dorsal integument are characters that this group shares only with M. heydenii. These two groups include the species of Mecinus not living on Plantago. Nevertheless, they seem to be not closely related on the basis of both a phylogenetic study of the adults and of molecular data as well as the examination of the immatures. The adults of the species related to M. janthinus are distinguishable from those related to M. heydenii by the less curved rostrum in lateral view, the shape of the penis, the distinctly longer flagellum and the completely unusual shape of the spermatheca that is reminiscent of the Cionini. The larvae and pupae differ in a series of characters in the chaetotaxy. Moreover, the immatures of this group possess some autapomorphies, i.e., in larvae four pds and usually three ss on the abdominal segments I–VIII and the surface of postlabium densely covered with asperities, and in pupae, the more or less elongated setae on the body and the abdominal segments I–VII dorsally with six or seven elongated, growing setae.

9 L3 larvae and 8 pupae, Serbia, Mihajlovac, 5.07.2009, 44°21.541'N, 22°28.650'E, 130 m., ex L. vulgaris; Serbia, Negotin, Tamnič, 2.08. 2007, 44°06.033'N, 22°30.105'E, 126 m., ex L. vulgaris; 8 pupae, Serbia, Mihajlovac, 5.07.2009, 44°21.683'N, 22°28.697'E, 125 m., ex L. vulgaris; 1 pupa, Serbia, DonjaKamenica, Kalna, 22.08.2011, 43°29.450'N, 22°19.712'E, 278 m., ex L. vulgaris. All collected by I. Toševski. Accession numbers of sequenced specimen MN992005.

(Figures 19A–D, 20A–F). Measurements (in mm). Body length: 4.00–4.75. Body width (metathorax and abdominal segments I–II): 1.10–1.25. Head width: 0.50–0.57.

Body (Figure 19A–D) yellowish, very slender, densely covered with asperities. Prothorax smaller than meso- and metathorax. Abdominal segments I–V of almost equal length; segments VI–IX decreasing gradually to the terminal body part; segment X reduced to three anal lobes of those lateral are the largest, and dorsal the smallest (sometimes absent). Chaetotaxy well developed, setae capilliform, variable in length, greyish or yellow. Prothorax (Figure 19B) with eight long prns of equal length; two long ps and one short eus. Meso- and metathorax (Figure 19B) with one very short prs, three pds, variable in length (pds₁ short, pds_2–3 medium), one short as, three short ss, one long eps, one long ps and one long eus. Pedal area with five long pda. Abdominal segments I–VIII (Figure 19C, D) with one very short prs, four pds of different length (on segments I–V: pds_1–2 short, pds_3–4 long; on segments VI–VIII all pds very long, almost equal in length) and arranged along posterior margin; one minute and two medium ss, one short and one long eps, one long ps, one long lsts and two medium eus. Abdominal segment IX (Figure 19D) with four very long ds, all located close to the posterior margin, two long ps and two short sts. Each of lateral anal lobe with two minute setae.

Figure 19. 

Mecinus janthinus mature larva, habitus and chaetotaxy A habitus of the body and frontal view of the head B lateral view of thoracic segments C lateral view of abdominal segment I D lateral view of abdominal segments VII–X. Abbreviations: Th. I–III – number of thoracic segments, Abd. I–X – number of abominal segments, setae: as – alar, ds – dorsal, eps – epipleural, eus – eusternal, lsts – laterosternal, pda – pedal, pds – postdorsal, prns – pronotal, prs – prodorsal, ps – pleural, ss – spiracular, sts – sternal, ts – terminal.

Head capsule (Figures 19A, 20A–F) yellow, distinctly narrowed bilaterally. Des_1–3,5 very long, equal in length; des₄ half the length of other des; des₄ medially. Fs_1,4,5 long, fs₃ medium. Les₁ and les₂ long, equal in length; one ves, and four pes short (Figure 20A). Two stemmata of different size. Antennae (Figure 20B) with sensorium (Se) conical, twice as long as wide, and three sensilla of different types: one sa and two sb. Clypeus (Figure 20C) trapezium-shaped, anterior margin distinctly concave; two cls relatively long, located on protuberances; clss placed medially between cls. Labrum (Figure 20C) with sinuate anterior margin; lrs_1-3 almost equal in length, all placed on protuberances. Epipharynx (Figure 20D) with three medium, finger-shaped als of almost equal length; two finger-like, different in length ams; two medium finger-like mes; surface smooth; labral rods close to kidney-shaped. Mandibles (Figure 20E) conical, wide, an elongated protuberance in the middle of the cutting edge; both mds capilliform, medium, equal in length, placed mediolaterally. Maxilla (Figure 20F) with one stps and two pfs of equal length; mbs medium; mala with six rod-like dms of almost equal size, five vms equal in length. Maxillary palpi: basal palpomere distinctly wider than distal, both of almost equal length. Prelabium (Figure 20F) cup-like with one very long prms; ligula with three medium ligs; premental sclerite clearly visible, cup-shaped. Labial palpi two-segmented; basal palpomere slightly wider and distinctly shorter than distal. Postlabium (Figure 20F) with three capilliform medium to long pms.

Figure 20. 

Mecinus janthinus mature larva, head and mouth parts A head, frontal view B antenna C clypeus and labrum, dorsal view D epipharynx E left mandible F maxillolabial complex, ventral aspect. Abbreviations: at – antenna, clss – clypeal sensorium, des – dorsal epicranial, lr – labral rods, sa – sensillum ampullaceum, sb – sensillum basiconicum, Se – sensorium, st – stemmata, setae: als – anterolateral, ams – anteromedial, cls – clypeal, dms – dorsal malar, fs – frontal, ligs – ligular, lrs – labral, ls – lateral epicranial, mbs – malar basiventral, mds – mandibular, mes – median, mxps – maxillary palp, pes – postepicranial, ves – ventral, pfs – palpiferal, pms – postlabial, prms – prelabial, stps – stipal, vms – ventral malar.

(Figure 21A–C). Measurements (in mm). Head width: 0.46–0.56. Body width: 1.16–1.50. Body length: 3.70–4.05.

Body elongated, white. Rostrum slender, about 3.4 times as long as wide, reaching almost up to mesocoxae. Antennae slender and elongated. Pronotum 1.1 times as wide as long. Mesonotum slightly shorter than metanotum. Urogomphi (ur) slender and elongated, conical, with sclerotised apex, distinctly reaching outline of the body, directed outside (Figure 21A–C).

Chaetotaxy well developed, setae short or medium long. Head with one vs, two sos, two os and two pas. Rostrum with one rs placed medially. All setae of head equal in length (Figure 21A, B). Pronotum with two as, one ds, two sls, two ls, and three pls (Figure 21B, C). All setae on pronotum elongated, equal in length (Figure 21C). Dorsal parts of meso- and metathorax with two setae placed medially. Abdominal segments I–VIII with two setae laterally and three medium long setae ventrally. Dorsal parts of abdominal segments I–VII with six setae (d₁ placed anteromedially, d_2–4 placed posteromedially, d_5–6 posterolaterally); segment VIII with five very long setae dorsally. Abdominal segment IX with two micro-setae ventrally.

Figure 21. 

Mecinus janthinus pupa habitus and chaetotaxy A ventral view B lateral view C dorsal view. Abbreviations: Th. I–III – number of thoracic segments, Abd. I–IX – number of abdominal segments, ur – urogomphi, setae: as – apical, d – dorsal, ds – discal, fes – femoral, l, ls – lateral, os – orbital, sls – postantennal, pls – posterolateral, rs – rostral, sls – superlateral, sos – superorbital, vs – vertical.

The host plant of M. janthinus is the yellow toadflax, Linaria vulgaris Mill. This species is distributed in temperate regions of the eastern Palearctic region, inhabiting lowlands and hilly slopes up to 500 m altitude. From beginning of the 1990s, M. janthinus was introduced as biological control agent for the control of invasive toadflaxes in North America (Toševski et al. 2018). The adults emerge in early March and feed intensively on the newly growing shoots of the host plant. Oviposition occurs on actively growing shoots, and the preferred oviposition site is the widest part of the stem. Females lay one or, rarely, two eggs per shoot. This species is a true stem borer with larval feeding and mining in the central part of the stem. The adults overwinter in the stems of the host plant inside an elongated pupal chamber built by the last instar larva prior to pupation.

Mecinus janthinus is largely distributed in northern, central and southeastern Europe, Russia from the western borders to southern central Siberia, the Caucasian states, and Turkey. This species was introduced in North America for the biological control of toadflaxes in 1991–1999 (Wilson et al. 2005). The adults can be easily confused with M. janthiniformis, both sympatric in part of their range of distribution, since the differences between them are few and subtle. In contrast, the larvae of these two species show numerous differences in the number of setae in many parts of the body, such as the head, antenna, pronotum and thoracic segments (see key).

2 L3 larvae, Mecedonia, Prilep, 25.07.2017, (41°17.354'N, 21°29.983'E, 618 m.) ex Linaria dalmatica macedonica 1 L3 larva, 4 pupae, Bulgaria, Harmanli, 17.08.2008, 41°53.117'N, 25°52.373'E, 310 m., ex Linaria genistifolia 12 L3 larva, Bulgaria, Harmanli, 17.07.2011, 41°53.117'N, 25°52.373'E, 310 m., ex L. genistifolia; 2 L3 larvae, 1 pupa, Bulgaria, Slatino, 7.08.2011, 42°09.981'N, 23°02.371'E, 390 m., ex L. genistifolia; 1 pupa, Serbia, Kalna, 1.09.2010., 43°29.450'N, 22°19.712'E, 278 m., ex L. genistifolia; 3 pupae, Serbia, Bovansko Jezero, Aleksinac, 12.08.2010, 43°37.735'N, 21°42.917'E, 231 m., ex L. genistifolia; North Macedonia, Veles, 10.09.2009, 41°44.332'N, 21°46.893'E, 201 m., ex L. genistifolia; 1 pupa, Serbia, Vranje, Golemo Selo, 20.08.2009, 42°44.203'N, 21°50.696'E, 523 m., ex L. genistifolia; 3 pupae, Bulgaria, Slatino, 7.08.2007, 42°09.981'N, 23°02.371'E, 390 m., ex L. genistifolia. All collected by I. Toševski. Accession numbers of sequenced specimen MN992006.

(Figures 22A–D, 23A–F). Measurements (in mm). Body length: 1.66–2.90. Body width (abdominal segments I–II): 0.66–1.10. Head width: 0.53–0.67.

Body (Figure 22A–D) yellowish. Prothorax smaller than meso- and metathorax. Abdominal segments I–VII of almost equal length; segments VIII and IX decreasing gradually to the terminal body part; segment X reduced to three anal lobes of those lateral are the largest, and dorsal the smallest (sometimes absent). Dorsum of abdominal segments I–VI divided into three lobes; on seventh into two lobes. Chaetotaxy well developed, setae various in length. Prothorax (Figure 22B) with eleven long prns; two medium ps and one medium eus. Meso- and metathorax (Figure 22B) with one short prs, three pds (pds₁ short, pds_2–3 medium), one medium as, three medium ss, one medium eps, one medium ps and one medium eus. Pedal area with six pda of different length (four of them placed on well isolated pedal sclerite). Abdominal segments I–VIII (Figure 22C, D) with one short prs, four pds (on segments I–V: pds_1,3 medium, pds_2,4 short; on segments VI–VIII all pds very long, equal in length), always arranged along the posterior margin, one minute and two long ss, one short and one medium eps, one medium ps, one medium lsts and two medium eus. Abdominal segment IX (Figure 22D) with four long ds located close to posterior margin, two ps different in length, and two short sts. Each of anal lobe (abd. segment X) with two minute setae.

Figure 22. 

Mecinus janthiniformis mature larva, habitus and chaetotaxy A habitus of the body and frontal view of the head B lateral view of thoracic segments C lateral view of abdominal segment I D lateral view of abdominal segments VII–X. Abbreviations: Th. I–III– number of thoracic segments, Abd. I–X – number of abominal segments, setae: as – alar, ds – dorsal, eps – epipleural, eus – eusternal, lsts – laterosternal, pda – pedal, pds – postdorsal, prns – pronotal, prs – prodorsal, ps – pleural, ss – spiracular, sts – sternal, ts – terminal.

Head capsule (Figures 22A, 23A–F) dark yellow, narrowed bilaterally. Des_1–3,5 very long, equal in length, des₄ twice shorter than other des; des₄ medially. Fs₁ as long as des₁, fs₃ short, fs_4,5 long. Les₁ and les₂ equal in length, slightly shorter than des₁; two ves and three pes very short (Figure 23A). Two stemmata of different size. Antennae (Figure 23B) with sensorium (Se) conical, twice as long as wide, and four sensilla basiconica (sb). Clypeus (Figure 23C) trapezium-shaped, anterior margin concave; two medium cls, clss clearly visible. Labrum (Figure 23C) with sinuate anterior margin; lrs₁ long, lrs₂ and lrs₃ medium. Epipharynx (Figure 23D) with three relatively long, finger-shaped als of almost equal length; two finger-shaped ams, equal in length; two rod-like mes of medium length; surface smooth; labral rods short, kidney shaped. Mandibles (Figure 23E) conical, wide, with a small protuberance in the middle of the cutting edge; both mds capilliform, relatively short, equal in length, placed mediolaterally. Maxilla (Figure 23F) with one stps and two pfs of equal length; mbs very short; mala with seven long finger-like dms of almost equal size, five vms different in length. Maxillary palpi: basal palpomere wider than distal, both of almost equal length. Prelabium (Figure 23F) cup-shaped with one very long prms; ligula with two relatively long ligs; premental sclerite clearly visible, cup-like. Labial palpi two-segmented; basal palpomere distinctly wider than distal, both almost equal in length. Postlabium (Figure 23F) with three medium pms.

Figure 23. 

Mecinus janthiniformis mature larva, head and mouth parts A head, frontal view B antenna C clypeus and labrum, dorsal view D epipharynx E left mandible F maxillolabial complex, ventral aspect. Abbreviations: at – antenna, clss – clypeal sensorium, des – dorsal epicranial, lr – labral rods, sb – sensillum basiconicum, Se – sensorium, st – stemmata, setae: als – anterolateral, ams – anteromedial, cls – clypeal, dms – dorsal malar, fs – frontal, ligs – ligular, lrs – labral, ls – lateral epicranial, mbs – malar basiventral, mds – mandibular, mes – median, mxps – maxillary palp, pes – postepicranial, ves – ventral, pfs – palpiferal, pms – postlabial, prms – prelabial, stps – stipal, vms – ventral malar.

(Figure 24A–C). Measurements (in mm). Head width: 0.46–0.66. Body width: 1.20–1.66. Body length: 3.22–4.16.

Body elongated, white. Rostrum slender, about four times as long as wide, reaching almost up to mesocoxae. Antennae slender and elongated. Pronotum 1.3 times as wide as long. Urogomphi (ur) slender and elongated, conical, with sclerotised apex, distinctly reaching outline of the body, directed outside (Figure 24A, C).

Chaetotaxy well developed, setae medium long or elongated, unequal length. Head with one long vs, two sos different in length, two os different in length and two sls different in length. Rostrum with one rs (Figure 24A). Pronotum with two as, one ds, two sls, two ls, and three pls (Figure 24B, C). All setae on prothorax elongated, equal in length (Figure 24C). Setae on head and rostrum shorter than those on prothorax. Dorsal parts of meso- and metathorax with three setae placed medially. Abdominal segments I–VIII with two setae placed laterally and three medium long setae ventrally. Dorsal parts of abdominal segments I–VII with six setae (d_1–4 placed posteromedially, d_5–6 posterolaterally); segment VIII with five very long setae dorsally. Abdominal segment IX with two micro-setae ventrally.

Figure 24. 

Mecinus janthiniformis pupa habitus and chaetotaxy A ventral view B lateral view C dorsal view. Abbreviations: Th. I–III – number of thoracic segments, Abd. I–IX – number of abdominal segments, ur – urogomphi, setae: as – apical, d – dorsal, ds – discal, fes – femoral, l, ls – lateral, os – orbital, sls – postantennal, pls – posterolateral, rs – rostral, sls – superlateral, sos – superorbital, vs – vertical.

The host plants of M. janthiniformis are Linaria genistifolia (L.) Mill. and L. dalmatica (L.) Mill., as well as all variable forms and hypothetical hybrids between these two plant species. Mecinus janthiniformis inhabits stands from lowlands to mountain pastures and meadows up to 1500 m. At the beginning of the 1990s, this species was introduced as a biological control agent for the control of invasive toadflaxes in North America (Toševski et al. 2018). Adults emerge in early spring and feed on the apical part of newly growing shoots. The females lay eggs over the next three months on the upper part of the main stem, including the lateral branches of the plant. Oviposition and larval development induce a slightly elongate gall in which the larvae pupate. The adults of this species overwinter inside the main stem of the host plant or inside induced galls on lateral branches (Toševski et al. 2011).

The distribution of M. janthiniformis follows that of the two host plants, L. genistifolia (L.) Mill. and L. dalmatica (eastern part of central and southeastern Europe to southern central Siberia, the northern Caucasian states and Turkey). Its separation from M. janthinus at the species level was clearly shown based on very careful biological and genetic studies (Toševski et al. 2011), but unfortunately, easy identification is only possible by collecting the specimens together with their host plants. Usually, in M. janthiniformis, the body is larger (length 3.2–6.0 mm), the apical part of the rostrum in females in lateral view is more curved, the punctures of the pronotum are slightly smaller and more densely adpressed, and the scales of the elytral interstriae are denser, arranged in two rows on part of several interstriae. The larvae of these two species show numerous differences in the number of setae in many parts of the body, whereas the differences are few in the pupae (see keys).

6 L3 larvae and 1 pupa, France, Provence-Alpes-Côte d’Azur, Alpes Maritimes, road Èze-La Turbie, 20.07.2014, on Antirrhinum latifolium Mill. stems, lgt. and det. R. Caldara. Accession numbers of sequenced specimen MN992007.

(Figures 25A–D, 26A–F). Measurements (in mm). Body length: 2.71–3.75. Body width (abdominal segments I–II): 1.10–1.25. Head width: 0.60–0.65.

Body (Figure 25A–D) yellowish, slender. All thoracic segments almost equal in length. Abdominal segments I–V of almost equal length; segments VI–IX decreasing gradually to the terminal body part; segment X reduced to three anal lobes of those lateral are the largest, and dorsal the smallest (sometimes absent). Chaetotaxy weakly developed, setae capilliform, variable in length, yellow. Prothorax (Figure 25B) with ten prns of unequal length (seven medium length, three short); two medium ps and one medium eus. Meso- and metathorax (Figure 25B) with one very short prs, three pds, different in length (pds_1,3 very short, pds₂ medium); one short as, three short ss, one medium long eps, one medium long ps and one medium eus. Pedal area with five pda, different in length. Abdominal segments I–VIII (Figure 25C, D) with one short prs, four pds of different length (pds_1,2,4 short, pds₃ medium; all pds on segments VI–VIII very long, equal in length) arranged along the posterior margin, one short and one medium ss, two medium eps, one medium ps, one medium lsts and two relatively long eus. Abdominal segment IX (Figure 25D) with three very long ds, all located close to the posterior margin, one medium ps and two medium sts. Each of lateral anal lobe with two minute setae.

Figure 25. 

Mecinus sicardi mature larva, habitus and chaetotaxy A habitus of the body and frontal view of the head B lateral view of thoracic segments C lateral view of abdominal segment I D lateral view of abdominal segments VII–X. Abbreviations: Th. I–III – number of thoracic segments, Abd. I–X – number of abominal segments, setae: as – alar, ds – dorsal, eps – epipleural, eus – eusternal, lsts – laterosternal, pda – pedal, pds – postdorsal, prns – pronotal, prs – prodorsal, ps – pleural, ss – spiracular, sts – sternal, ts – terminal.

Head capsule (Figures 25A, 26A–F) yellow, distinctly narrowed bilaterally. Des_1–3,5 equal in length, des₄ twice shorter than other des. Fs_1,4,5 long, equal in length, fs₃ medium. Les₁ and les₂ medium, equal in length; two ves short; four pes spine-like (Figure 26A). Two stemmata of different size. Antennae (Figure 26B) with sensorium (Se) conical, twice as long as wide, located medially, and three sensilla of different types: one sa and two sb. Clypeus (Figure 26C) trapezium-shaped, anterior margin slightly concave; two medium cls, located posteromedially; clss clearly visible. Labrum (Figure 26C) close to semi-circular, anterior margin sinuate; lrs_1-3 almost equal in length. Epipharynx (Figure 26D) with three rod-shaped als of almost equal length; two medium, finger-like ams; one medium, finger-like mes; surface smooth; labral rods short and relatively wide. Mandibles (Figure 26E) conical, wide, with small protuberance in the middle of the cutting edge; both mds capilliform, medium, equal in length, placed transversely. Maxilla (Figure 26F) with one stps and two pfs of equal length; mbs short; mala with six rod-like dms of almost equal size, five vms different in size. Maxillary palpi: basal palpomere slightly wider than distal, both of almost equal length. Prelabium (Figure 26F) cup-like with one long prms; ligula with three minute ligs; premental sclerite clearly visible, cup-shaped, posterior extension with acute apex. Labial palpi two-segmented; basal palpomere distinctly wider than distal, both of almost equal length. Postlabium (Figure 26F) with three pms; pms₁ and pms₃ short, pms₂ three times as long as pms₁.

Figure 26. 

Mecinus sicardi mature larva, head and mouth parts A head, frontal view B antenna C clypeus and labrum, dorsal view D epipharynx E left mandible F maxillolabial complex, ventral aspect. Abbreviations: at – antenna, clss – clypeal sensorium, des – dorsal epicranial, lr – labral rods, sa – sensillum ampullaceum, sb – sensillum basiconicum, Se – sensorium, st – stemmata, setae: als – anterolateral, ams – anteromedial, cls – clypeal, dms – dorsal malar, fs – frontal, ligs – ligular, lrs – labral, ls – lateral epicranial, mbs – malar basiventral, mds – mandibular, mes – median, mxps – maxillary palp, pes – postepicranial, ves – ventral, pfs – palpiferal, pms – postlabial, prms – prelabial, stps – stipal, vms – ventral malar.

(Figure 27A–C). Measurements (in mm). Head width: 0.60–0.70. Body width: 1.75–2.00. Body length: 3.75–4.50.

Body elongated, white. Rostrum moderately slender, about 3.5 times as long as wide, reaching up to mesocoxae. Antennae elongated. Pronotum 1.8 times as wide as long. Urogomphi (ur) slender, conical, with sclerotised apex, both directed outside, distinctly reaching outline of the body (Figure 27A–C).

Chaetotaxy setae medium or elongated. Head with one vs, two sos and two os. Rostrum with one pas. Setae on head and rostrum straight, as long as those on prothorax (Figure 27A). Pronotum with two as, two sls, two ls, one ds and four pls. Dorsal parts of meso- and metathorax with three setae equal in length setae placed medially. Abdominal segments I–VIII with three very short setae ventrally and two setae laterally. Dorsal parts of abdominal segments I–VII with six setae growing gradually from segment I to VII (d₁ placed anteromedially, d_2–5 placed posteromedially, d₆ posterolaterally); segment VIII with five elongated setae dorsally. Abdominal segment IX with two micro-setae ventrally.

Figure 27. 

Mecinus sicardi pupa habitus and chaetotaxy A ventral view B lateral view C dorsal view. Abbreviations: Th. I–III – number of thoracic segments, Abd. I–IX – number of abdominal segments, ur – urogomphi, setae: as – apical, d – dorsal, ds – discal, fes – femoral, l, ls – lateral, os – orbital, sls – postantennal, pls – posterolateral, rs – rostral, sls – superlateral, sos – superorbital, vs – vertical.

The host plant of this species, at least in Côte d’Azur, is Antirrhinum latifolium Mill. As reported by Caldara and Fogato (2013), larvae feed on the larger stems of the plant and dig tunnels, causing at most very small lateral deformations. They pupate in summer, and adults stay inside the plant until the spring of the following year. Before pupation, however, the mature larvae leave the main tunnel, which runs longitudinally, and produce a small oblique tunnel that ends just in proximity of the external cuticle of the stem. Therefore, when leaving their cells, adults have only to bore a thin layer, although in the meantime, the plant has become dry and hard.

The adults of this rare species, with a narrow range of distribution – in fact, it is known in a few localities of southeastern Spain, eastern and southern France, and north-western Italy – differ from the other species studied here by the black elytra instead of blue. Due to this character, this species may be superficially confused with M. pyraster, from which it is easily distinguishable by the elytral vestiture composed of scales that are uniformly arranged and are all recumbent. The rostrum (in dorsal view) is distinctly wider, and the pronotum has sides slightly more rounded and is usually widest towards the middle. Finally, ventrite 5 of the male lacks a tuft of hairs, and the shape of the penis is different.

The larvae of this species differ from the others of the group by the abdominal segments I–VIII with two ss (instead of three) and asperities covering only the posterior part of postlabium, whereas pupae differ in having the rostrum with only one sls (instead of two) and without rs and the pronotum with four pls (instead of three).

Larva. (1) cuticle of the body tuberculate; (2) pedal lobes weakly isolated; (3) abdominal segment X reduced to three anal lobes of those lateral are the largest, and dorsal the smallest (sometimes absent); (4) thoracic spiracle unicameral; (5) abdominal setae very short to medium, become progressively longer from abdominal segment I to VIII; (6) abdominal segments I–VIII with three pds and two ss; (7) head brown, flattened laterally; (8) frontal suture poorly or well visible; (9) endocarina 4/5 of the frons; (10) des₄ three times shorter than des₁; (11) fs₁ usually absent; (12) absence of fs₂ except one species; (13) fs₃ very short; (14) head with two stemmata; (15) absence of cls₁; (16) labial palpi one-segmented; (17) premental sclerite U-shaped; (18) surface of postlabium smooth.

Pupa. (1) body very slender and elongated; (2) urogomphi short, only slightly reaching outline of the body, directed downward; (3) rostrum slender and elongated; (4) setae minute; (5) head with one os; (6) rostrum with without or with one sls and one rs; (7) pronotum with without or with up to two as, one ds, without or with one sls, without or with one ls, three pls; (8) meso- and metanotum with three setae; (9) abdominal segments I–VII with three or five setae dorsally.

The adults of this group are characterised by the rostrum in the basal half strongly and abruptly curved, the elytra distinctly elongate, and the dorsal integument black or blue, usually with metallic reflections apart from several characters of the male and female genitalia. In immatures, the autapomorphies seem limited to a U-shaped premental sclerite in larvae.

This group seems more closely related to the M. janthinus group than to other groups of Mecinus in both morphological characters (shape of body and colour of dorsal integument) and biology (hosts in Plantaginaceae other than Plantago). However, the species of the M. heydenii group clearly differ from those of the M. janthinus group by the rostrum being strongly curved in the basal half and by the shape of the penis and spermatheca. The study of immatures also did not show close relationships between these two unique groups living on Antirrhineae, since the species of the M. heydenii group have one palpomere on the labial palpi instead of two, and all spiracles are unicameral. The pupae also differ somewhat in the shape of the urogomphi, which are shorter, only slightly reaching the outline of the body, and directed downward. The setae of the head and pronotum are also shorter, and the dorsal setae of abdominal segments I–VII are less numerous.

4 L3 larvae and 6 pupae, Serbia, Negotin, 1.07.2017, 44°16.610'N, 22°30.480'E, 71 m., ex L. vulgaris, lgt. I. Toševski. Accession numbers of sequenced specimen MN992002.

(Figures 28A–D, 29A–F). Measurements (in mm). Body length: 2.16–2.66. Body width (metathorax or abdominal segments I–II): 0.83–1.00. Head width: 0.30–0.33.

Body (Figure 28A–D) white-yellowish, very slender. Chaetotaxy weakly developed, setae (except pronotum and dorsal part of abdominal segment IX) extremely short, difficult to observe. Prothorax (Figure 28B) with four medium and four very short prns, two very short ps and one very short eus. Meso- and metathorax (Figure 28B) with one short prs, three short pds, one very short as, three minute ss, one very short eps, one very short ps and one very short eus. Pedal area with four very short pda. Abdominal segments I–VIII (Figure 28C, D) with one very short prs, three very short pds arranged along the posterior margin, two minute ss, two very short eps, one very short ps, one very short lsts and two very short eus. Abdominal segment IX (Figure 28D) with two ds (one medium and one very short), all located close to the posterior margin, one medium ps and two very short sts. Each lateral anal lobe with two minute setae.

Figure 28. 

Mecinus heydenii mature larva, habitus and chaetotaxy A habitus of the body and frontal view of the head B lateral view of thoracic segments C lateral view of abdominal segment I D lateral view of abdominal segments VII–X. Abbreviations: Th. I–III – number of thoracic segments, Abd. I–X – number of abominal segments, setae: as – alar, ds – dorsal, eps – epipleural, eus – eusternal, lsts – laterosternal, pda – pedal, pds – postdorsal, prns – pronotal, prs – prodorsal, ps – pleural, ss – spiracular, sts – sternal, ts – terminal.

Head capsule (Figures 28A, 29A–F) pale yellow, distinctly narrowed bilaterally. Frontal suture poorly visible. Des_1–3,5 very long, equal in length; des₄ four times shorter than other des₁. Fs₁ and fs₂ absent, fs₃ very short, fs₄ and fs₅ long. Les₁ shorter than les₂; two ves and four pes short (Figure 29A). Antennae (Figure 29B) with sensorium (Se) conical, thrice as long as wide, and three sensilla of different types: one sa and two sb. Clypeus (Figure 29C) trapezium-shaped, anterior margin slightly concave; cls₂ relatively long; clss clearly visible. Labrum (Figure 29C) with sinuate anterior margin; lrs₁ long, lrs₂ slightly shorter than lrs₁, lrs₃ two times shorter than lrs₁. Epipharynx (Figure 29D) with three medium, finger-shaped als of almost equal length; two rod-like, different in length ams; two finger-like mes of medium length; surface smooth; labral rods close to kidney-shaped. Mandibles (Figure 29E) conical, wide, with a small protuberance in the middle of the cutting edge; both mds capilliform, medium, equal in length, placed mediolaterally. Maxilla (Figure 29F) with one stps and two pfs long, of equal length; mbs very short; mala with six finger-like dms different in length (dms_1,2 medium, dms_3–6 long to very long), five vms different in length. Maxillary palpi: basal palpomere distinctly wider than distal, both of almost equal length. Prelabium (Figure 29F) almost rounded with one very long prms; ligula with two ligs different in length; premental sclerite clearly visible, U-shaped. Postlabium (Figure 29F) with short pms₁, long pms₂, and short pms₃.

Figure 29. 

Mecinus heydenii mature larva, head and mouth parts A head, frontal view B antenna C clypeus and labrum, dorsal view D epipharynx E left mandible F maxillolabial complex, ventral aspect. Abbreviations: at – antenna, clss – clypeal sensorium, des – dorsal epicranial, lr – labral rods, sa – sensillum ampullaceum, sb – sensillum basiconicum, Se – sensorium, st – stemmata, setae: als – anterolateral, ams – anteromedial, cls – clypeal, dms – dorsal malar, fs – frontal, ligs – ligular, lrs – labral, ls – lateral epicranial, mbs – malar basiventral, mds – mandibular, mes – median, mxps – maxillary palp, pes – postepicranial, ves – ventral, pfs – palpiferal, pms – postlabial, prms – prelabial, stps – stipal, vms – ventral malar.

(Figure 30A–C). Measurements (in mm). Head width: 0.30–0.60. Body width: 0.73–1.13. Body length: 2.33–2.93.

Body elongated, white. Rostrum slender, about five times as long as wide, but reaching up only to procoxae. Antennae slender and elongated. Pronotum 1.4 times as wide as long. Urogomphi (ur) very short, conical, with sclerotised apex, reaching outline of the body, directed downward (Figure 30A–C).

Chaetotaxy sparse, setae short, unequal length. Head with one os. Rostrum with one rs placed medially. Setae on head and rostrum straight, as long as those on prothorax (Figure 30A). Pronotum with two as, one ds and three pls. Dorsal parts of meso- and metathorax with three setae placed medially. Abdominal segments I–VIII with one seta laterally and three very short setae ventrally. Dorsal parts of abdominal segments I–VII with five setae (d₁ placed anteromedially, d_2–4 posteromedially, d₅ posterolaterally); segment VIII with four setae dorsally. Abdominal segment IX with two micro-setae ventrally.

Figure 30. 

Mecinus heydenii pupa habitus and chaetotaxy A ventral view B lateral view C dorsal view. Abbreviations: Th. I–III – number of thoracic segments, Abd. I–IX – number of abdominal segments, ur – urogomphi, setae: as – apical, d – dorsal, ds – discal, fes – femoral, l, ls – lateral, os – orbital, pls – posterolateral, rs – rostral.

This monophagous species is associated with yellow toadflax, Linaria vulgaris Mill. The adults are active from early spring, following the appearance of the first growing shoots of its host plant. The adults exhibit extreme cryptic behavior, which makes them difficult to collect. Oviposition occurs on actively growing young shoots, usually in the top or middle part of the stem. Females often lay several eggs distributed along the host plant shoot. Oviposition provokes primitive shoot swelling and hypertrophy that leads to the formation of a pseudo-gall of the young shoot. Larval development occurs inside this pseudo-gall, and pupation takes place in larval chambers prepared very close to the stem surface. Emerged adults stay inside the stem until August, when all adults leave their host plant within a two-week period. Overwintering takes place in the soil litter near the host plant.

This species is widely distributed in Europe and is the only one of its group present in northern Europe, from Germany to Sweden. The adult is distinguishable by the rostrum very strongly curved from base to apex, especially before antennal insertion, in both sexes. However, it is somewhat difficult to morphologically separate this taxon from the two cryptic species M. peterharrisi and M. laeviceps. They are well distinguishable, however, by molecular and biological data (Toševski et al. 2014).

The study of the immatures allowed us to add numerous other interesting differences: larvae of M. heydenii differ from those of M. laeviceps by the pronotum with eight prns (instead of nine), the thoracic segments with three pds (instead of two), each pedal lobe with four pda (instead of three), pds of abdominal segments I–VIII distinctly smaller, and the head with four pes (instead of one). Both species differ from M. peterharrisi by fs₁ and fs₂ absent and the antennae with two sb (instead of four).

The pupae of the three species are also slightly different in the presence or lack of some setae on the rostrum and pronotum (without sls and ls in M. heydenii and M. peterharrisi, respectively) and femora (with fes in M. heydenii and M. laeviceps), and their number in the abdominal segments.

8 L3 larvae and 10 pupae, Serbia, Slankamen, 22.06.2017 45°08.343'N, 20°15.042'E, 177 m., ex Linaria genistifolia, lgt. I. Toševski. Accession numbers of sequenced specimen MN992003.

(Figures 31A–D, 32A–F). Measurements (in mm). Body length: 1.67–2.67. Body width (abdominal segments I–II): 0.37–0.83. Head width: 0.30–0.40.

Body (Figure 31A–D) yellowish, slender. Chaetotaxy rather weakly developed, setae capilliform, variable in length, light yellow. Prothorax (Figure 31B) with nine prns of unequal length (eight relatively long, one medium); two long ps and one medium eus. Meso- and metathorax (Figure 31B) with one short prs, two pds, different in length (medium, long), one short as, three short ss, one medium eps, one medium ps and one medium eus. Pedal area with three pda, different in length. Abdominal segments I–VIII (Figure 31C, D) with one short prs, three pds of different length (pds_1,3 short, pds₂ medium; all pds on segment VIII very long, equal in length), arranged along the posterior margin, two short ss, two short eps, one medium ps, one short lsts and two short eus. Abdominal segment IX (Figure 31D) with two long ds, located close to posterior margin, one long ps and two short sts. Each lateral anal lobe with one minute seta.

Figure 31. 

Mecinus laeviceps mature larva, habitus and chaetotaxy A habitus of the body and frontal view of the head B lateral view of thoracic segments C lateral view of abdominal segment I D lateral view of abdominal segments VII–X. Abbreviations: Th. I–III – number of thoracic segments, Abd. I–X – number of abominal segments, setae: as – alar, ds – dorsal, eps – epipleural, eus – eusternal, lsts – laterosternal, pda – pedal, pds – postdorsal, prns – pronotal, prs – prodorsal, ps – pleural, ss – spiracular, sts – sternal, ts – terminal.

Head capsule (Figures 31A, 32A–F) light yellow, distinctly narrowed bilaterally. Des_1–3,5 long, equal in length; des₄ very short; des₄ located in the central part of epicranium. Fs₃ short to very short, fs_4,5 long, equal in length. Les₁ and les₂ long, equal in length; two ves and one pes very short (Figure 32A). Antenna (Figure 32B) with sensorium (Se) conical, three times as long as wide, and three sensilla: one sa and two sb. Clypeus (Figure 32C) trapezium-shaped, anterior margin slightly concave; cls₂ medium; clss placed close to cls₂. Labrum (Figure 32C) almost semi-circular, anterior margin sinuated; lrs₁ long, both lrs₂ and lrs₃ medium. Epipharynx (Figure 32D) with three finger-like als of almost equal length; two finger-like ams, both medium; two short finger-like mes, surface smooth; labral rods short, kidney-shaped. Mandibles (Figure 32E) conical, wide, with a small protuberance in the middle of the cutting edge; both mds capilliform, medium, equal in length, placed transversely. Maxilla (Figure 32F) with one stps and two pfs of equal length; mbs short; mala with six rod-like dms different in length (dms_1,2 medium, dms_3–6 long to very long), five vms different in length. Maxillary palpi: basal palpomere wider than distal, both of almost equal length. Prelabium (Figure 32F) oval-shaped with one long prms; ligula with two short ligs; premental sclerite clearly visible, U-shaped. Postlabium (Figure 32F) with very short pms₁, long pms₂, and medium pms₃.

Figure 32. 

Mecinus laeviceps mature larva, head and mouth parts A head, frontal view B antenna C clypeus and labrum, dorsal view D epipharynx E left mandible F maxillolabial complex, ventral aspect. Abbreviations: at – antenna, clss – clypeal sensorium, des – dorsal epicranial, lr – labral rods, sa – sensillum ampullaceum, sb – sensillum basiconicum, Se – sensorium, st – stemmata, setae: als – anterolateral, ams – anteromedial, cls – clypeal, dms – dorsal malar, fs – frontal, ligs – ligular, lrs – labral, ls – lateral epicranial, mbs – malar basiventral, mds – mandibular, mes – median, mxps – maxillary palp, pes – postepicranial, ves – ventral, pfs – palpiferal, pms – postlabial, prms – prelabial, stps – stipal, vms – ventral malar.

(Figure 33A–C). Measurements (in mm). Head width: 0.35–0.40. Body width: 0.87–1.07. Body length: 2.12–2.50.

Body elongated, white. Rostrum slender, about four times as long as wide, reaching up to mesocoxae. Antennae slender and elongated. Pronotum 1.5 times as wide as long. Urogomphi (ur) very short, conical, with sclerotised apex, only slightly reaching outline of the body, directed downward (Figure 33B, C).

Chaetotaxy sparse, setae short, unequal length. Head with one os. Rostrum with one rs and one pas. Setae on head and rostrum straight, as long as those on prothorax (Figure 33A). Pronotum with one as, one ls, one ds and three pls. Dorsal parts of meso- and metathorax with three setae placed medially. Abdominal segments I–VIII with three very short setae ventrally, distributed in regular lines. Dorsal parts of abdominal segments I–VII with five setae (d₁ placed anteromedially, d_2–4 posteromedially, d₅ posterolaterally); segment VIII with four setae dorsally. Abdominal segment IX with two micro-setae ventrally.

Figure 33. 

Mecinus laeviceps pupa habitus and chaetotaxy A ventral view B lateral view C dorsal view. Abbreviations: Th. I–III – number of thoracic segments, Abd. I–IX – number of abdominal segments, ur – urogomphi, setae: as – apical, d – dorsal, ds – discal, fes – femoral, l, ls – lateral, os – orbital, sls – postantennal, pls – posterolateral, rs – rostral.

This is a monophagous species associated with broomleaf toadflax, Linaria genistifolia (L.) Mill. The adults are active from early spring, following the appearance of the growing shoots of its host plant. The adults feed intensively on shoot points and apical leaves. Females oviposit batches of 3–6 eggs into the lower to middle part of the young growing shoots. Larval development usually induces stunted growth in the young shoot. The larvae develop in the central part of the stem, forming a relatively short tunnel and the formation of a pseudo-gall in which pupation takes place in the larval chamber very close to the stem surface. Like M. heydenii, the adults stay inside the stem until mid-August, when all adults leave their host plants. Adults overwinter in the soil close to the host plant.

There are three cryptic subspecies of this species that are distinguishable by molecular and biogeographical data (Toševski et al. 2014). We studied the nominal subspecies distributed in the Czech Republic, Hungary, northern Serbia, and southern Russia; the subspecies meridionalis Toševski & Jović, 2014 is distributed in Serbia and Bulgaria and the subspecies corifoliae Toševski & Jović, 2014 is distributed in Turkey. As reported in the remarks on M. heydenii, several characters allow us to distinguish this last species and M. peterharrisi from M. laeviceps.

25 L3 larvae and 20 pupae, Mecedonia, Prilep, 25.07.2017, (41°17.354'N, 21°29.983'E, 618 m.) ex Linaria dalmatica macedonica, lgt. I. Toševski. Accession numbers of sequenced specimen MN992004.

(Figures 34A–D, 35A–F). Measurements (in mm). Body length: 2.00–3.75. Body width (metathorax and abdominal segments I–II): 0.65–1.00. Head width: 0.35–0.43.

Body (Figure 34A–D) yellowish, very slender. Chaetotaxy weakly developed, setae extremely short, difficult to observe. Prothorax (Figure 34B) with nine short prns; two short ps and one short eus. Meso- and metathorax (Figure 34B) with one short prs, two short pds, one short as, three minute ss, one short eps, one short ps and one short eus. Pedal area with four short pda. Abdominal segments I–VIII (Figure 34C, D) with one short prs, three short pds arranged along the posterior margin, two minute ss, two short eps, one short ps, one short lsts and two short eus. Abdominal segment IX (Figure 34D) with two ds located close to the posterior margin, one short ps and two short sts. Each of anal lobe with two minute setae.

Figure 34. 

Mecinus peterharrisi mature larva, habitus and chaetotaxy A habitus of the body and frontal view of the head B lateral view of thoracic segments C lateral view of abdominal segment I D lateral view of abdominal segments VII–X. Abbreviations: Th. I–III – number of thoracic segments, Abd. I–X – number of abominal segments, setae: as – alar, ds – dorsal, eps – epipleural, eus – eusternal, lsts – laterosternal, pda – pedal, pds – postdorsal, prns – pronotal, prs – prodorsal, ps – pleural, ss – spiracular, sts – sternal, ts – terminal.

Head capsule (Figures 34A, 35A–C) pale yellow, distinctly narrowed bilaterally. Frontal suture well visible. Des_1–3,5 very long, equal in length; des₄ three times shorter than other des. Fs₁ as long as des₁, fs₂ and fs₃ very short, fs_4–5 long. Les₁ shorter than les₂; two ves and four pes very short (Figure 35A). Two stemmata of different size. Antennae (Figure 35B) with sensorium (Se) conical, thrice as long as wide, located medially, and three sensilla of different types: one sa and four sb. Clypeus (Figure 35C) trapezium-shaped, anterior margin slightly concave; cls₂ medium; clss clearly visible. Labrum (Figure 35C) with sinuate anterior margin; lrs₁ very long, lrs₂ shorter than lrs₁, lrs₃ three times shorter than lrs₁. Epipharynx (Figure 35D) with three relatively long, finger-shaped als of almost equal length; two rod-like ams, equal in length; two rod-like mes of medium length; surface smooth; labral rods short, rounded. Mandibles (Figure 35E) conical, wide, with a small protuberance in the middle of the cutting edge; both mds capilliform, relatively long, equal in length, placed mediolaterally. Maxilla (Figure 35F) with one stps and two pfs of equal length; mbs very short; mala with six finger-like dms different in length (dms_1,2 medium, dms_3–6 long to very long), five vms different in length. Maxillary palpi: basal palpomere wider than distal, both of almost equal length. Prelabium (Figure 35F) close to oval-shaped with one very long prms; ligula with two ligs of equal length; premental sclerite clearly visible, U-shaped. Postlabium (Figure 35F) with short pms₁, long pms₂, and short pms₃.

Figure 35. 

Mecinus peterharrisi mature larva, head and mouth parts A head, frontal view B antenna C clypeus and labrum, dorsal view D epipharynx E left mandible F maxillolabial complex, ventral aspect. Abbreviations: at – antenna, clss – clypeal sensorium, des – dorsal epicranial, lr – labral rods, sa – sensillum ampullaceum, sb – sensillum basiconicum, Se – sensorium, st – stemmata, setae: als – anterolateral, ams – anteromedial, cls – clypeal, dms – dorsal malar, fs – frontal, ligs – ligular, lrs – labral, ls – lateral epicranial, mbs – malar basiventral, mds – mandibular, mes – median, mxps – maxillary palp, pes – postepicranial, ves – ventral, pfs – palpiferal, pms – postlabial, prms – prelabial, stps – stipal, vms – ventral malar.

(Figure 36A–C). Measurements (in mm). Head width: 0.36–0.43. Body width: 0.83–1.50. Body length: 2.46–3.66.

Body elongated, slender, white. Rostrum slender, about five times as long as wide, reaching up to mesocoxae. Antennae slender and moderately elongated. Pronotum 1.1 times as wide as long. Urogomphi (ur) very short, conical, with sclerotised apex, reaching outline of the body, directed downward (Figure 36A, B).

Chaetotaxy sparse, setae very short, equal in length. Head with one os. Rostrum with one rs placed medially. Setae on head and rostrum straight, as long as those on prothorax (Figure 36A). Pronotum with one ds, one sls and three pls. Dorsal parts of meso- and metathorax with three setae placed medially. Abdominal segments I–VIII with one seta laterally, two very short setae ventrally and three setae dorsally, placed along posterior margin. Abdominal segment IX with two micro-setae ventrally. (Figure 36B).

Figure 36. 

Mecinus peterharrisi pupa habitus and chaetotaxy A ventral view B lateral view C dorsal view. Abbreviations: Th. I–III – number of thoracic segments, Abd. I–IX – number of abdominal segments, ur – urogomphi, setae: as – apical, d – dorsal, ds – discal, fes – femoral, l – lateral, os – orbital, pls – posterolateral, rs – rostral, sls – superlateral.

This species is known only from the southwest region of North Macedonia and northwestern part of Greece following the distribution of Linaria dalmatica macedonica (Griseb.) D.A. Sutton, as well as from sparse populations of L. dalmatica dalmatica (L.) Mill. present at the Montenegrin Sea coast in the vicinity of Kotor Bay (Toševski et al. 2014). Adults appear in the field at the beginning of March and aggregate on young growing shoots, causing significant damage to the shoot points and apical leaves. Like M. laeviceps, the larvae develop within short larval tunnels, and the newly emerged adults remain and feed in the pupal chamber until mid-August. Adults overwinter in the soil close to the host plant.

This species, found only in the Balkans (Macedonia, Greece, Montenegro) as above reported, is very similar to M. laeviceps, from which it differs by the body being more robust and usually longer, the integument of the pronotum more distinctly bluish, and the penis with longer tip. Moreover, the vestiture is usually formed by slightly broader scales and is therefore generally more distinct. As reported in the remarks on M. heydenii and in the keys, the study of the immatures has revealed other interesting differences between these three species that are very useful for their separation.