Research Article |
Corresponding author: Marcin Kadej ( marcin.kadej@uwr.edu.pl ) Academic editor: Thomas Philips
© 2018 Marcin Kadej.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Kadej M (2018) Larva and pupa of Ctesias (s. str.) serra (Fabricius, 1792) with remarks on biology and economic importance, and larval comparison of co-occurring genera (Coleoptera, Dermestidae). ZooKeys 758: 115-135. https://doi.org/10.3897/zookeys.758.24477
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Updated descriptions of the last larval instar (based on the larvae and exuviae) and first detailed description of the pupa of Ctesias (s. str.) serra (Fabricius, 1792) (Coleoptera: Dermestidae) are presented. Several morphological characters of C. serra larvae are documented: antenna, epipharynx, mandible, maxilla, ligula, labial palpi, spicisetae, hastisetae, terga, frons, foreleg, and condition of the antecostal suture. The paper is fully illustrated and includes some important additions to extend notes for this species available in the references. Summarised data about biology, economic importance, and distribution of C. serra are also provided. The comparison of larval characteristics for some of the genera of Dermestidae co-occurring with Ctesias is presented. A key for identification of these genera is also provided.
exuvia, immature stage, larva, pupa, seta, terga
The genus Ctesias Stephens, 1830 is placed in the tribe Megatomini in the subfamily Megatominae. According to the world catalogue of Dermestidae, the genus contains only 26 species (
Interestingly, of the 21 species of Ctesias, the larval stages of only one, Ctesias serra (Fabricius, 1792), are referred to in the literature (compare with Table
The current work is a continuation of the previous articles devoted to study the morphology of the immature stages of Dermestidae (
List of Ctesias species with references related to larval morphological characters.
Taxa | References | Available data |
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Ctesias Stephens, 1830 |
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Short sentence in key (p. 167) |
Beal 1967 | Short sentence in key (p. 290) | |
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Short sentences in key (p. 168) [in German] | |
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Short sentences in key (p. 37) | |
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Short sentences in key (p. 31–32) [in German] | |
Ctesias (s. str.) serra (Fabricius, 1792) |
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Brief description of larval morphology (p. 339) [in French], illustration of larval habitus, antenna, setae (p. 345, pl. IX, fig. 4f) |
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Short description of larval morphology (p. 27) [in French] and illustration of habitus (p. 27) | |
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Brief description of larval morphology (p. 162), pupa (p. 162) | |
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Illustration of apex of maxilla (p. 267), mouthparts (ventral, p. 267), habitus (lateral view, p. 267) | |
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Illustration of antenna (p. 163) | |
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Short sentence in key (p. 7), brief description of larval morphology (p. 12), and illustration of antenna (p. 15), epipharynx (p. 18) | |
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Short description in key (p. 150), illustration of habitus (p. 154, pl. II) | |
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Short sentence in key (p. 168) [in German], illustration of habitus (p. 169) | |
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Short description in key (p. 37) and on pages 43, 60, illustration of larval habitus (p.120), epipharynx (p. 128) [epipharynx shown after |
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Illustration of habitus (dorsal, lateral view, p. 34), antenna (p. 34), epipharynx (p. 34) [habitus and epipharynx shown after |
For morphological examination of larvae and exuviae of the last-stage, specimens stored in ethanol were used. The material came from the collection of the Department of Invertebrate Biology, Evolution and Conservation, University of Wrocław (DIBEC). Larva/exuvium were boiled for 3–10 minutes in 10% solution of KOH, and then rinsed with distilled water. They were then placed in distilled water for ~1 hour to clean and soften the material. All structures were put in glycerin on slides. The morphological structures were studied under a Nikon Eclipse E 600 phase contrast microscope with a drawing tube attached, and a Nikon SMZ-800 binocular microscope; examination was done using transmitted light. Photos were taken with Canon 500D and Nikon Coolpix 4500 cameras under Nikon Eclipse 80i and/or Nikon SMZ-800. In addition to the description provided herein, plates of the larval habitus/pupa as well as drawings of selected elements are also provided.
The terminology used in this paper follows
ac acrotergite;
as antecostal suture (ridge);
asg abdominal segments;
b transverse row of placoid sensillae on epipharynx;
c claw;
cs campaniform sensilla;
dst distal epipharyngeal sensillae;
dmr dorsomesal row of setae on lacinia;
er epipharyngeal rods;
f femur;
fe fore wing;
g galea;
hw hind wing;
l lacinia;
lp labial palp(i);
mp mesal pair of labor-epipharyngeal setae;
ms mesonotum;
msr mesal row of setae on lacinia;
mt metanotum;
mxp maxillary palp(i);
p2 second pair of labor-epipharyngeal setae;
pls placoid sensilla;
pr pretarsus;
pro pronotum;
prs processes;
s sensorium (accessory sensory papillae);
sbp subproximal epipharyngeal sensillae;
st stipes;
t tibia;
tr tubercula.
(2 larvae) Polonia, Brzóza distr. Kozienice 7.VII.1956, w próchnie pnia lipy [inside the mould of the trunk of linden Tilia spp.], leg. B. Burakowski, det. M. Mroczkowski 1956; (2 larvae) Polonia, Maciejowice distr. Kozienice 6.VII.1956, w próchnie (bielu) dębu koło chodników Anobiidae [inside the mould of the oak Quercus spp. next to corridors of Anobiidae], leg. B. Burakowski, det. M. Mroczkowski 1956; (1 larva) Polonia, Maciejowice distr. Kozienice 6.VII.1956, pod korą olchy [under the bark of alder Alnus spp.], leg. B. Burakowski, det. M. Mroczkowski 1956; (7 larvae) Puszcza Kampinoska, Sieraków, 31.X.1952, pod kora dębu [under the bark of the oak Quercus spp., leg. M. Mroczkowski]; (1 exuvia, 1 pupa) Warszawa, Saska Kępa pod korą wierzby [under the bark of willow Salix spp.] 10.V.1955, leg. M. Mroczkowski; (1 exuvia, 4 larvae) Polonia, Dojlidy ad. Białystok 19.III.1959 leg. R. Bielawski, det. M. Mroczkowski 1959; (1 larva) Germania: Brandenburg, Berlin, Schorfheide, 1.IV.1994. leg. A. Herrmann, coll. A. Herrmann. All materials (except for the last larva) are deposited in the Department of Invertebrate Biology, Evolution and Conservation, University of Wrocław, Przybyszewskiego 65, PL–51–148 Wrocław, Poland.
Larva, last instar. Length 5.0–7.0 mm. Body fusiform, relatively long, rather flattened, not hunchbacked. Integument of head, nota and terga yellowish brown to brown; tergal plates sclerotised (Fig.
Mature larva of Ctesias (s. str.) serra (Fabricius, 1792). 7 Antenna (dorso-fronto-lateral) 8 Frons (dorsal; large circles with rings represent points of insertion of large scaly-like spicisetae, small circles represent points of insertion of nudisetae (= lanceolate spicisetae)) 9 Mandible (dorsal) 10 Mandible (lateroventral) 11 Epipharynx (ventral) 12 Apex of lacinia (dorsal) 13 Maxilla (ventral) 14 Labium (ventral) 15 Labial palpi (ventral). Scale bars: 0.1 mm.
Antecostal suture on notum I absent, but distinct on nota II–III and abdominal terga I–VII (Figs
Mature larva of Ctesias (s. str.) serra (Fabricius, 1792). 16 Pronotum (dorsal, left half, denuded; large circles represent points of insertion of large spicisetae, small circles along the suture represent points of insertion of hastisetae) 17 Right protosternal leg (dorsal) 18 Abdominal tergum I (dorsal, left half, denuded; large circles represent points of insertion of large spicisetae, small circles represent points of insertion of hastisetae) 19 Abdominal tergum VII (dorsal, right half, denuded; large circles represent points of insertion of large spicisetae, small circles along the suture represent points of insertion of short setae, small circles below large circles represents points of insertions of hastisetae) 20 Abdominal tergum VIII (dorsal, right half, denuded; large circles represent points of insertion of large spicisetae, small circles along the suture represent points of insertion of short setae) 21 Abdominal tergum IX (dorsal, denuded; circles represent points of insertion of large spicisetae). Scale bars: 0.1 mm.
Pupa (Figs
Knowledge of the biology of the species is limited, with only a small amount of published information (
Probably because of its rarity, this species has no serious economic importance. However, it is likely that in its natural habitat it can play a positive role in reducing the number of eggs of butterflies classified as pest of forests (
Widely distributed in Europe (from the Mediterranean region to the UK and the southern province of Fennoscandia). It has been also recorded from Algeria, Caucasus and Russia (Stavropol) (
Most of the larval morphological characteristics presented here are shown for the first time for C. serra. In comparison with previous papers of
However, the morphology of epipharynx is quite interesting. Structures shown by
It is difficult to compare larval characters of C. serra with congenerics because of a lack of larval morphological descriptions for the other species. For this reason I decided to collect and summarise larval data for the genera which co-occur with Ctesias (see Table
Comparison of larval characteristics for some of the genera of Dermestidae co-occurring with Ctesias serra.
Character | Body shape | Colour of integument | Tegites/Sternites | Urogomphi | Abdominal tufts of hastisetae |
---|---|---|---|---|---|
Genus | |||||
Dermestes Linnaeus, 1758 | Elongate, cylindrical (gradually tapering to last abdominal segment; ratio length to width 1.0:4.5); broadest at notum III; without caudal brush of long, slender setae | Usually dark brown to black, but sometimes yellowish and sometimes with median yellowish strip from anterior margin of pronotum | Tergites usually strongly sclerotised. Sternites membranous (= hyaline), but those of abdominal segments IX-X, and occasionally VII-X, entirely sclerotised | Present on abdominal tergite IX dorsally | Absent |
Thylodrias Motschulsky, 1839 | Compact and C-shaped, cyphosomatic (ratio length to width 1.0:3.0); broadest at abdominal segment I; without caudal brush of long, slender setae | Light golden brown | Tergites sclerotised. Sternites membranous (= hyaline) | Absent | Absent |
Trinodes Dejean, 1821 | Relatively short (= compact, ratio length to width 1.0:2.5); broadest at abdominal segment I; without caudal brush of long, slender setae | Greyish with sclerotised brown strip along anterior and posterior margin of tergite, enclosing a transverse membranous area on each side | Tergites sclerotised. Sternites membranous (= hyaline) | Absent | Absent |
Attagenus Latreille, 1802 | Elongate, cylindrical, orthosomatic (gradually tapering to last abdominal segment; ratio length to width 1.0:6.0); broadest at notum I; with caudal brush of long, slender setae | Yellowish brown to brown | Tergites sclerotised. Sternites membranous (= hyaline) | Absent | Absent |
Anthrenus Geoffroy, 1762 | Relatively short (= compact, ratio length to width 1.0:2.5); broadest at abdominal terga IV–VI1; flattened, not hunchbacked and not constricted; slender setae present on tergum IX, but not so long as in Attagenus, Ctesias, Megatoma, Reesa, Trogoderma | Yellowish brown to dark brown; sometimes with darker spots or patches on terga | Tergites sclerotised. Sternites sometimes sclerotised | Absent | On membranous area behind terga V–VII |
Ctesias Stephens, 1830 | Fusiform, and relatively long, sub-oblong (ratio length to width 1.0:3.0); broadest at notum III; rather flattened, not hunchbacked; constricted behind abdominal terga I–III; with caudal brush of long, slender setae | Yellowish brown to brown; thoracic terga (= nota I–III) sometimes with darker spots or patches | Tergites sclerotised. Sterna I–VIII with central median line with strongly sclerotised and shiny strip | Absent | On membranous area behind terga IV–VII |
Globicornis Latreille, 1829 | Fusiform, and relatively long, sub-oblong (ratio length to width approx. 1.0:4.5); broadest at notum III; slightly hunchbacked; with caudal brush of long, slender setae | Brown to dark brown | Tergites sclerotised. Sternites membranous (= hyaline) | Absent | On terga V–VIII2 (never on membranes behind terga) |
Megatoma Herbst, 1792 | Fusiform, and relatively long (ratio length to width 1.0:4.5); broadest at notum III; flattened, not hunchbacked; with caudal brush of long, slender setae | Yellowish brown (in some species thoracic terga I–III with distinctly dark brown patches at sides, sometimes extending to middle on terga II and III) | Tergites sclerotised. Sternites membranous (= hyaline) | Absent | On terga VI –VIII (never on membranes behind terga) |
Reesa Beal, 1967 | Fusiform, and relatively long (ratio length to width 1.0:4.0); broadest at notum III; rather flattened, not hunchbacked, orthosomatic; with caudal brush of long, slender setae | Yellowish brown to dark brown (then strongly pigmented) | Tergites sclerotised. Sternites membranous (= hyaline) | Absent | On terga I–VIII (but the longest and thickest on VI–VIII) (never on membranes behind terga) |
Trogoderma Dejean, 1821 | Fusiform, and relatively long (ratio length to width 1.0:2.0); broadest at notum III; rather flattened, not hunchbacked, orthosomatic; with caudal brush of long, slender setae | Yellowish brown to dark brown | Tergites sclerotised. Sternites membranous (= hyaline) | Absent | On terga V(VI)–VIII (longest and thickest on VI–VIII) (never on membranes behind terga) |
Continuation of the comparison of larval characteristics for some of the genera of Dermestidae co-occurring with Ctesias serra.
Character | Body setation | Ratio length to width of head of hastiseta | Antecostal suturae | Epipharynx | Setae Mp/p2 on labro-epipharyengal margin |
---|---|---|---|---|---|
Genus | |||||
Dermestes Linnaeus, 1758 | Hastisetae absent (only spicisetae present, occasionally modified into ramous setae or club-shaped setae) | N/A | Distinct, present on nota II–III and abdominal terga I–X | No distal epipharyngeal sensilla (dst) | Middle 4 setae of labro-epipharyengal margin consisting of 2 spatulate, broad inner (Mp) and 2 stout, narrow (p2) outer setae |
Thylodrias Motschulsky, 1839 | Hastisetae absent (club-shaped setae present3; spinulate setae only on transverse membranous areas of each tergite, not on pronotum) | N/A | Distinct, present on nota II–III and abdominal terga I–VIII | No distal epipharyngeal sensilla (dst) | Middle 4 setae of labro-epipharyengal margin consisting of 4 spatulate, broad setae both in inner (Mp) and (p2) outer setae |
Trinodes Dejean, 1821 | Hastisetae absent (black, erect spicisetae present) | N/A | Distinct, present on nota II–III and abdominal terga I–VIII | No distal epipharyngeal sensilla (dst) | Middle 4 setae of labro-epipharyengal margin consisting of 2 spatulate, broad inner (Mp) and no setae (p2) in outer series4 |
Attagenus Latreille, 1802 | Hastisetae absent (only spinulate (= lanceolate) and in some species also scale-like setae present) | N/A | Distinct, present on nota II–III and abdominal terga I–VIII | Usually 2 distal epipharyngeal sensilla (dst) present, but not enclosed by furrow (sometimes dst absent) | Middle 4 setae of labro-epipharyengal margin consisting of 2 spatulate, broad inner (Mp) and 2 stout, narrow (p2) outer setae |
Anthrenus Geoffroy, 1762 | Both hastisetae and spicisetae present | Head of hastisetae variable: 3 to more than 5 times as long as wide at the widest point | Present on nota II-III, incomplete on abdominal tergites I–IV; sometimes slightly visible on tergum V | Distal epipharyngeal sensillae (dst) arranged in one group of 6, but not enclosed by furrow (usually sensillae are in a faintly defined fusiform area) | Middle 4 setae of labro-epipharyengal margin consisting of 2 spatulate, broad inner (Mp) and 2 stout, narrow (p2) outer setae |
Ctesias Stephens, 1830 | Both hastisetae and spicisetae present | Head of hastisetae more than 3 times as long as wide at the widest point | Absent on notum I, but distinct on nota II–III and abdominal terga I–VII (Figs |
Distal epipharyngeal sensillae (dst) arranged in one group of 6 (in two longitudinal series of 3 sensillae), not enclosed by distinct furrow | Middle 4 setae of labro-epipharyengal margin consisting of 2 spatulate, broad inner (Mp) and 2 stout, narrow (p2) outer setae |
Globicornis Latreille, 1829 | Both hastisetae and spicisetae present | Head of hastisetae less than 3 (e.g. G. corticalis and G. emarginata), or more than 3 times as long as wide at the widest point (e.g. G. nigripes) |
Absent on notum I, but distinct on nota II and III as well as abdominal terga I–VIII (on segment VIII its form reminds thread-like carina) | Distal epipharyngeal sensilla arranged in two groups: one of two sensillae, and second of four sensillae; both groups completely enclosed/encircled by a furrow (except G. nigripes in which six distal sensillae are enclosed in one ring); besides in G. corticalis and G. emarginata apices of the epipharyengal rods are joined by a sclerotised transverse bar | Middle 4 setae of labro-epipharyengal margin consisting of 2 spatulate, broad inner (Mp) and 2 stout, narrow (p2) outer setae |
Megatoma Herbst, 1792 | Both hastisetae and spicisetae present | Head of hastisetae more than 3 times as long as wide at the widest point | Smooth and distinct, present on nota I–III and abdominal terga I–VIII (absent on segment VIII in subgenus Pseudohadrotoma) | Distal epipharyngeal sensillae arranged in one group of 6 in two rows | Middle 4 setae of labro-epipharyengal margin consisting of 4 spatulate, broad setae both in inner (Mp) and (p2) outer setae |
Reesa Beal, 1967 | Both hastisetae and spicisetae present | Head of hastisetae more than 3 times as long as wide at the widest point | Absent on notum I, but distinct and denticulate on nota II–III and abdominal terga I–IX | Distal epipharyngeal sensillae arranged in one group (enclosed in distinct ring) of 6 | Middle 4 setae of labro-epipharyengal margin consisting of 2 spatulate, broad inner (Mp) and 2 stout, narrow (p2) outer setae |
Trogoderma Dejean, 1821 | Both hastisetae and spicisetae present | Head of hastisetae less than 3 times as long as wide at the widest point | Not always well defined; if present usually absent on abdominal segment VIII, but in those rare instances when it is present, it is weak and interrupted at several points | Distal epipharyngeal sensillae arranged in one group (enclosed in distinct ring) of 4-6(7) or sometimes in two rings of 2 and 4 | Middle 4 setae of labro-epipharyengal margin consisting of 2 spatulate, broad inner (Mp) and 2 stout, narrow (p2) outer setae |
Continuation of the comparison of larval characteristics for some of the genera of Dermestidae co-occurring with Ctesias serra.
Character | # of stemmata | Antenna | Maxillary palp | Pretarsal setae |
---|---|---|---|---|
Genus | ||||
Dermestes Linnaeus, 1758 | 65 | Antennal segment 2 more than twice (3-4x) as long as segment 3; sensorium arising from apex of segment 2 and never terminates at apex of segment 3 | 4 segments | Equal |
Thylodrias Motschulsky, 1839 | 3 | Antennal segment 2 much narrower and shorter than segment 1 and half as long as segment 3; sensorium arising from apex of segment 2 and terminates at middle of segment 3 | 4 segments | Unequal (anterior seta shorter than posterior one) |
Trinodes Dejean, 1821 | 6 | Antennal segment 2 nearly as long and broad, as segment 1 and less than half as long as segment 3; sensorium arising from basal third of segment 2 and terminates almost at apex of segment 3 | 4 segments | Unequal (anterior seta shorter than posterior one) |
Attagenus Latreille, 1802 | 4–56 | Antennal segment 2 more than twice (3-4x) as long as segment 3; sensorium arising from apex of segment 2 and never terminates at apex of segment 3 | 4 segments | Probably variable – depends on species |
Anthrenus Geoffroy, 1762 | 6 | Antennal segment 2 more than twice as long as segment 3; sensorium arising from apex of segment 2 and never terminates at apex of segment 3 | 3 segments | Variable – depends on species |
Ctesias Stephens, 1830 | 6 | Antennal segment 2 more than twice as long as segment 3; sensorium in ventral position – only sometimes slightly extending above apex of segment 2 | 3 segments | Subequal |
Globicornis Latreille, 1829 | 6 | Antennal segment 2 twice as long as segment 3; sensorium in ventral position, below the apex of segemnt 2 | 3 segments | Equal (e.g. G. corticalis, G. emarginata and G. nigripes7) |
Megatoma Herbst, 1792 | 5(?)8 | Antennal segment 2 twice as long as segment 3; sensorium in ventral position, below the apex of segemnt 2 | 3 segments | Equal |
Reesa Beal, 1967 | 4 | Antennal segment 2 not more than half as long as segment 3; sensorium in ventral position, below the apex of segemnt 2; antennal segment 2 with at least one seta (sometimes two setae) | 3 segments | Subequal |
Trogoderma Dejean, 1821 | 5 | Antennal segment 2 not more than half as long as segment 3; antennal segment 2 either without setae or with one-two seta(e) | 3 segments | Variable – depends on species |
Moreover, because Ctesias serra inhabits quite similar habitats (= in or near spider webs, under loose bark, in old decayed wood) as some of the representatives of the genera Anthrenus (e.g. A. fuscus Olivier, 1789 or A. museorum (Linnaeus, 1761)), Globicornis (e.g. G. corticalis (Eichhoff, 1863) or G. emarginata (Gyllenhal, 1808)), Megatoma (e.g. M. undata (Linnaeus, 1758)) or Trinodes (e.g. T. hirtus (Fabricius, 1781)), I have identified morphological characters that could aid precise determination. The first characteristic that is useful in distinguishing Ctesias serra from other species is body shape. In C. serra it is constricted at abdominal terga I–III, and the body is broadest at notum III (ratio length to width 1.0:3.0), while in the rest of the genera there is no constriction. The body is broadest at abdominal segments IV–VI in Anthrenus, at notum III or abdominal segment I in Globicornis and Megatoma (ratio length to width 1.0:4.5), and at abdominal segment I in Trinodes (ratio length to width 1.0:2.5).
Also the integument colour is distinctly different in Globicornis (dark brown to black) and Trinodes (greyish with a sclerotised brown strip along the anterior and posterior margin of the tergite, enclosing a transverse membranous area on each side), while in Ctesias it is yellowish brown to brown (and thoracic terga (= nota I–III) sometimes with darker spots or patches). Megatoma is also yellowish brown (in some species have thoracic terga I–III with distinctly dark brown patches at sides, sometimes extending to middle on terga II and III). Only in Ctesias do the sterna I–VIII have a central median line with a strongly sclerotised and shiny strip.
Other differences involve morphology and the location of abdominal tufts of hastisetae. In Ctesias and Anthrenus they are situated behind abdominal terga and always on membranous areas, while in Globicornis and Megatoma they are located on sclerotised areas on abdominal terga (and never on membranes behind the terga). Trinodes do not have hastisetae. In Ctesias there are four tufts of hastisetae (on the membranous area behind the abdominal terga IV–VII), while in Anthrenus there are only three (on the membranous area behind the abdominal terga V–VII). Additionally, in Trogoderma-like Megatomini such as Megatoma, dense brushes of hastisetae are dark brown and compact (hastisetae are shorter and densely packed under the terga), while in Ctesias the hastisetae are lighter (= brown or yellowish brown), longer, and are loosely packed. For other features see Table
A separate comment is required regarding pupae since, as for the larvae, there are no detailed descriptions of the morphology of this stage for Ctesias except for a brief description at the generic level by
Pupae of C. serra lack gin-traps. These occur in Dermestini Latreille, 1804 or Attagenini Laporte de Castelnau, 1840 and are thought to protect soft-bodied pupae from predators or parasites, like mites (
It is noteworthy that the pupae of C. serra have two urogomphi-like processes on the IX abdominal segment. Typical urogomphi are mainly known from the larval stages of Dermestes Linnaeus, 1758, Orphilus Erichson, 1846 and Thorictodes Reitter, 1875 (
1 | Urogomphi on IX abdominal tergite dorsally | Dermestes L., 1758 |
– | Urogomphi on IX abdominal tergite dorsally absent | 2 |
2 | Abdominal tufts of hastisetae absent | 3 |
Abdominal tufts of hastisetae present | 5 | |
3 | Body cylindrical, broadest at notum I; with caudal brush of long, slender setae | Attagenus Latreille, 1802 |
– | Body compact, broadest at abdominal segment I, without caudal brush of long, slender set | 4 |
4 | Body uniformly light golden brown; posterior margin of terga with club-shaped setae; antennal segment 2 much narrower and shorter than segment 1 and half as long as segment 3; sensorium arising from apex of segment 2 and terminates at middle of segment 3 | Thyodrias Motschulsky, 1839 |
– | Body brown or greyish with sclerotised brown strip along anteriorand posterior margin of tergite, enclosing a transverse membranous area on each side; posterior margin of terga without club-shaped setae – black, long, stout spicisetae present; antennal segment 2 nearly as long and broad, as segment 1 and less than half as long as segment 3; sensorium arising from basal third of segment 2 and terminates almost at apex of segment 3 | Trinodes Dejean, 1821 |
5 | Abdominal tufts of hastisetae on membranous area behind terga | 6 |
– | Abdominal tufts of hastisetae on terga (never on membranous area behind terga) | 7 |
6 | Body broadest at notum III and constricted behind abdominal terga I–III; caudal brush of long, slender setae present; abdominal tufts of hastisetae on membranous area behind terga IV–VII; sterna I–VIII with central median line with strongly sclerotised and shiny strip | Ctesias Stephens, 1830 |
– | Body broadest at abdominal terga IV–VI and not constricted; slender setae present on terga IX, but not so long as it is in Ctesias; abdominal tufts of hastisetae on membranous area behind terga V–VII | Anthrenus Geoffroy, 1762 |
7 | Antennal segment 2 twice as long as segment 3 | 8 |
– | Antennal segment 2 not more than half as long as segment 3 | 9 |
8 | Terga brown to dark brown; abdominal tufts of hastisetae on terga V–VIII | Globicornis Latreille, 1829 |
– | Terga yellowish brown (in some species thoracic terga I–III with distinctly dark brown patches at sides, sometimes extending to middle on terga II and III); abdominal tufts of hastisetae on terga VI–VIII | Megatoma Herbst, 1792 |
9 | Abdominal tufts of hastisetae on terga I–VIII; antecostal suture absent on notum I, but distinct and denticulate on nota II–III and abdominal terga I–IX; head of hastisetae more than 3 times as long as wide at the widest point | Reesa Beal, 1967 |
– | Abdominal tufts of hastisetae on terga V (VI)–VIII; antecostal suture not always well defined; if present usually absent on abdominal segment VIII, but in those rare instances when it is present, it is weak and interrupted at several points head of hastisetae less than 3 times as long as wide at the widest point | Trogoderma Dejean, 1821 |
I thank Dr. Deborah Harvey (RHUL, UK) for commenting on a draft of the manuscript. My special thanks are due to the reviewers Dr. Valentina Filippini (Spain), one anonymous reviewer, and Dr. Keith Philips (USA) for valuable suggestions on the manuscript. This study was funded by the Institute of Environmental Biology, Faculty of Biological Science, University of Wrocław, Poland (project no. 1076/Ś/IBŚ/2018).