Research Article |
Corresponding author: Qiang Li ( liqiangkm@126.com ) Corresponding author: Li Ma ( maliwasps@aliyun.com ) Academic editor: Michael Ohl
© 2019 Nawaz Haider Bashir, Qiang Li, Li Ma.
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:
Bashir NH, Li Q, Ma L (2019) Review of the genus Stigmus Panzer (Hymenoptera, Crabronidae) in China, with description of five new species from the Oriental and Palearctic Regions. ZooKeys 843: 51-69. https://doi.org/10.3897/zookeys.843.31885
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Five new species of the genus Stigmus: S. capoblongus Bashir & Ma, sp. n., S. denticorneus Bashir & Ma, sp. n., S. fronticoncavus Bashir & Ma, sp. n., S. interruptus Bashir & Ma, sp. n. and S. lobomelanicus Bashir & Ma, sp. n. are described and illustrated from China. Also, a key to the species of Stigmus Panzer occurring in China is provided.
Hymenoptera, new species, Pemphredoninae, Stigmus
The genus Stigmus Panzer was erected by
The diagnostic characteristics that differentiate Stigmus from other genera in Pemphredonini are the presence of occipital carina; mandibles in the male bidentate, in the female uni-, bi-, or usually tridentate; vertex micropore field (opaque area) present; labrum subtriangular, pentagonal or trapeziform; face with a shallow scapal basin; interantennal tubercle absent; clypeus of male with silvery dense setae; eyes broadly separated, pitted grooves along orbits narrow or absent; head moderately developed behind eyes; pronotum with a transverse carina; notauli indicated or developed; omaulus well developed (only in S. solskyi A. Morawitz is it invisible against the background of a wrinkled mesopleuron sculpture); no definitive episternal sulcus; stigma large, two submarginal cells; hindwing media diverging before or beyond cu-a, hindwing median cell normal size; petiole at least twice its diameter; and female pygidial plate present (
In the present study, five new species of genus Stigmus Panzer are described and illustrated. A key to the species of the genus Stigmus reported from China is also provided.
The specimens examined in this study belong to the following institutions: Insect Collections of China Agricultural University, Beijing, P. R. China (
The specimens were observed and illustrated with the help of an Olympus stereomicroscope (SZ Series, Japan) with an ocular micrometer. For the terminology we mainly followed
PR and OR represent Palearctic and Oriental Regions, respectively.
Females (unknown for S. capoblongus sp. n)
1 | Clypeus deeply impressed, not produced (OR) | S. fronticoncavus sp. n. |
– | Clypeus flat or slightly convex, slightly or strongly produced | 2 |
2 | Scrobal suture inconspicuous, lacking or just a single weak carina (PR) | S. denticorneus sp. n. |
– | Scrobal suture narrow or broad, slenderly or distinctly crenate (OR) | 3 |
3 | Ventral surface of petiole shiny, without carina | S. kansitakuanus Tsuneki |
– | Ventral surface of petiole with a few strong longitudinal carinae medially and posteriorly | 4 |
4 | Ventral gena with large dense punctures mixed with several irregular rugae laterally; lateral surface of petiole with several irregular rugae and two strong lateral carinae medially and posteriorly | S. lobomelanicus sp. n. |
– | Ventral gena shiny, smooth; lateral surface of petiole with a few strong longitudinal carinae medially and posteriorly | 5 |
5 | Pronotal collar with strong lateral carinae, forming round antero-lateral angle; inner orbital furrow broad, shiny, slenderly rugulose | S. murotai (Tsuneki) |
– | Pronotal collar without lateral carina or carina incomplete, without antero-lateral angle; inner orbital furrow lacking | 6 |
6 | Occipital carina complete, distinctly crenulate; scutellum with midsize sparse punctures, median line weakly impressed; posterior surface of propodeum with sturdy reticulation | S. shirozui alishanus Tsuneki |
– | Occipital carina incomplete, not crenulate; scutellum with fine sparse punctures, without median line; posterior surface of propodeum with sparse, longitudinal rugae or irregular rugae | 7 |
7 | Mesoscutum with large punctures, anterior and posterior area with dense longitudinal micro sculptures; vertex with few punctures; pronotal collar with sturdy incomplete anterior carina | S. interruptus sp. n. |
– | Mesoscutum with tiny punctures, without micro sculpture or slightly coriaceous anteriorly; vertex impunctate; pronotal collar with strong complete anterior carina | 8 |
8 | Dorsal surface of petiole distinctly widened toward apex; lateral surface of propodeum with contiguous, slender or sturdy, oblique rugae; admedian and parapsidal line weakly impressed; median and upper frons impunctate; pygidial area impunctate, with dense longitudinal rugae | S. convergens ami Tsuneki |
– | Dorsal surface of petiole slightly widened toward apex; lateral surface of propodeum reticulate; admedian and parapsidal line distinct; median and upper frons with fine punctures; pygidial area with two lines of large punctures, without rugae | S. japonicus Tsuneki |
Males (unknown for S. fronticoncavus sp. n. and S. interruptus sp. n.)
1 | Clypeus nearly flat or flat (OR) | 2 |
– | Clypeus reflected toward apex | 3 |
2 | Frontal furrow lacking; parapsidal line weakly impressed; vertex behind ocelli impunctate | S. lobomelanicus sp. n. |
– | Frontal furrow fine and weak on upper frons, anteriorly deeper, broader and distinct; parapsidal line distinct; vertex behind ocelli with fine punctures | S. kansitakuanus Tsuneki |
3 | Scrobal suture inconspicuous, lacking, or just a single weak carina (PR) | S. denticorneus sp. n |
– | Scrobal suture broad, distinctly crenate and complete (OR) | 4 |
4 | Pronotal collar with strong lateral carinae, forming round antero-lateral angle | S. murotai (Tsuneki) |
– | Pronotal collar without lateral carina, without antero-lateral angle | 5 |
5 | Median and upper frons with punctures; vertex behind ocelli with punctures; propodeal enclosure U-shaped medially; dorsal surface of petiole slightly widened toward apex | 6 |
– | Median and upper frons impunctate; vertex behind ocelli impunctate; propodeal enclosure triangular medially; dorsal surface of petiole distinctly widened toward apex | 7 |
6 | Frontal furrow weakly impressed; gena with fine punctures; admedian line weakly impressed; pronotal lobe white; tegula yellowish | S. capoblongus sp. n |
– | Frontal furrow distinctly impressed; gena with midsize punctures; admedian line distinctly impressed; pronotal lobe ivory; tegula dark brown | S. japonicus Tsuneki |
7 | Gena finely punctate; mesoscutum with tiny punctures; admedian and parapsidal line weakly impressed | S. convergens ami Tsuneki |
– | Gena impunctate; mesoscutum with large punctures; admedian and parapsidal line distinctly impressed | S. shirozui alishanus Tsuneki |
Type species. Stigmus pendulus Panzer, 1804, by monotypy.
Holotype: ♂, China: Gansu: Dangxian: Daheba, 35°32'N, 105°17'E, 30.VII.2004, 2003m, No. 200707614, coll. Qiong Wu (ZJU); Paratypes: 3♂, China: Gansu: Dangxian: Daheba, 35°32'N, 105°17'E, 30.VII.2004, 2530m, No. 200707818, 200707830, coll. Min Shi, No. 200707834, coll. Qiong Wu (ZJU); 1♂, China: Shanxi: Liuba: Ziboshan, 38°19'N, 111°28'E, 2004.VIII.3, 1632m, No .200707852, coll. Min Shi (ZJU); 1♂, China: Henan: Funiushan Mount, 33°37'N, 111°43'E, 10.VII.1996, No. 973367, coll. Ping Cai (ZJU).
Differs from S. japonicus
Male (Figs
Measurements. BL: 5–5.5 mm; HW : HLD : HLF = 76 : 43 : 57; HW : EWd : EW : TW : EL = 76 : 23 : 26 : 20 : 46; length of scape : length of pedicel : length of flagellomere I : width of flagellomere I : length of flagellomere II : width of flagellomere II = 21 : 8 : 9 : 3 : 8 : 3; PL : PW : LTI : WTI = 38 : 8 : 36 : 40.
Colour pattern. Clypeus with reddish brown to dark brown band subapically; mandible yellowish except reddish brown apically; palpi ivory; scape beneath ivory, above fulvous; pedicel fulvous; flagellomere beneath fulvous, above I fulvous, remaining reddish brown to dark brown; pronotal lobe white; tegula yellowish; forewing veins brown; fore leg: yellowish to fulvous except outer margin of femur somewhat brown, coxa dark brown largely; mid leg: yellowish to fulvous except outer margin of femur somewhat brown, coxa dark brown largely; hind leg: coxa apically, trochanter, base and apex of femur, tibia largely, tarsi yellowish to fulvous, remainder dark brown; petiole black; gaster dark brown, gastral sterna II–VII posteriorly bright yellow; setae on clypeus silvery and mandible yellow.
Head.
Mandible bidentate apically (Fig.
Stigmus capoblongus Bashir & Ma, sp. n. (male). a Frontal view of head b dorsal view of head c dorsal view of collar d dorsal view of propodeum e dorsal view of petiole and gastral tergum I f lateral view of petiole and gastral tergum I g dorsal view of male genitalia h lateral view of male genitalia i ventral view of male genitalia. Scale bars: 1 mm (a–f); 1.24 mm (g–i).
Mesosoma.
Pronotal collar with strong carinae anteriorly, lateral carina lacking, without antero-lateral corner (Fig.
Legs. Normal, outer surface of hind tibia with three long, slender, fulvous to dark brown, spines.
Wings. Forewing venation typical for genus Stigmus, hindwing media diverging beyond cu-a.
Metasoma.
Dorsal surface of petiole subquadrate (cross section), slightly convex and widened toward apex slightly, and with two sturdy, longitudinal median carinae, area between carinae with dense, sturdy, irregular rugae, median and posterior areas with two sturdy, longitudinal, lateral carinae on each side (Fig.
Female. Unknown.
China (Gansu, Shanxi).
The specific name, capoblongus, is derived from the Latin cap- (= head) and the Latin word oblongus (= oblong), referring to the oblong head.
Holotype: ♀, China: Gansu: Dangxian: Daheba, 35°32'N, 105°17'E, 30.VII.2004, 2530m, No. 200707781, coll. Qiong Wu (ZJU); Paratypes: 1♀7♂, China: Gansu: Dangxian: Daheba, 35°32'N, 105°17'E, 30.VII.2004, 2530m, ♀, No. 200707788, 7♂, No. 200707785, 200707812, 200707771, 200707795, 200707816, 200707814, 200707829, coll. Qiong Wu, Min Shi (ZJU).
Distinguished from S. japonicus by combination of characters: in female, free margin of clypeus slightly produced and with two distinct cornuted teeth medially, deeply emarginated in the middle; scrobal suture inconspicuous, just with several longitudinal rugae; lateral surface of petiole with two strong longitudinal carinae; admedian and parapsidal line weakly impressed; posterior surface of propodeum with a shallow narrow median groove, shiny, remaining with contiguous punctures and sparse irregular oblique longitudinal rugae. Closely related to S. quadriceps except antenna dark brown; forewing veins brown; gena with sparse midsize to large punctures dorsally; in male, frontal furrow distinctly impressed on upper frons; free margin of clypeus slightly produced and nearly truncate medially; anterior area of pronotal collar narrowly emarginated in middle, antero-lateral corner lacking; petiole subquadrate (non-cylindrical), slightly convex, not longer than 1st abdominal tergite.
Female (Figs
Measurements. ♀ BL: 5 mm; HW : HLD : HLF = 68 : 42 : 52; HW : EWd : EW : TW : EL = 68 : 15 : 20 : 21 : 42; length of scape : length of pedicel : length of flagellomere I : width of flagellomere I : length of flagellomere II : width of flagellomere II = 20 : 8 : 6 : 4 : 6 : 4; PL : PW : LTI : WTI = 37 : 9 : 32 : 38. ♂, BL: 3.8–4.2 mm; HW : HLD : HLF = 62 : 36 : 48; HW : EWd : EW : TW : EL = 62 : 16 : 21 : 14 : 38; length of scape : length of pedicel : length of flagellomere I : width of flagellomere I : length of flagellomere II : width of flagellomere II = 15 : 7 : 6 : 3 : 7 : 3.5; PL : PW : LTI : WTI = 34 : 10 : 28 : 28.
Colour pattern. Clypeus with reddish brown to dark brown band subapically; mandible yellowish except reddish brown apically; labrum dark brown; palpi fulvous; antenna beneath fulvous and dark brown; pronotal lobe ivory; tegula fulvous; forewing veins brown; fore and mid legs: base and apex of femur, tibia, tarsi fulvous, trochanter and remaining femur dark brown; hind leg basal one fourth of tibia and tarsus fulvous, remaining tibia dark brown; petiole black; gaster dark brown; setae on clypeus and mandible yellow.
Head.
Mandible tridentate apically, median tooth larger (Fig.
Stigmus denticorneus Bashir & Ma, sp. n. (a–g female h–l male). a, h Frontal view of head b, i dorsal view of head c dorsal view of collar d dorsal view of propodeum e dorsal view of petiole and gastral tergum I f lateral view of petiole and gastral tergum I g dorsal view of pygidial plate j dorsal view of male genitalia k lateral view of male genitalia l ventral view of male genitalia. Scale bars: 1 mm (a, b, d–f, h, i); 1.63 mm (c, g, j–l).
Mesosoma.
Anterior area of pronotal collar with sturdy carinae (incomplete), narrowly emarginated in middle, lateral carina lacking, antero-lateral corner lacking (Fig.
Legs. Normal, outer surface of hind tibia with three long, slender, fulvous to dark brown, spines.
Wings. Forewing venation typical for genus Stigmus, hindwing media diverging beyond cu-a.
Metasoma.
Dorsal surface of petiole subquadrate (cross section), slightly convex and widened toward apex slightly, with two strong longitudinal carinae, and irregular, strong rugae anteriorly and medially, lateral area with 2 strong longitudinal carinae posteriorly on each side (Fig.
Male
(Figs
China (Gansu).
The specific epithetic, is derived from the Latin dent- (= tooth) and the Latin word corneus (= cornuted), referring to the free margin of clypeus with two distinct cornuted teeth medially.
Holotype ♀, China: Yunnan: Ruili: Mengxiu, 24°05'N, 97°47'E, 2.V.1981, coll. Fasheng Li (
Similar to S. murotai (Tsuneki, 1977) but differ by clypeus impunctate; free margin of clypeus not produced, with two small teeth medially, nearly truncate apically; labrum five lobed; ventral surface of petiole smooth, without carina; gena impunctate; parapsidal line weakly impressed; pygidial area broadened triangular shaped. S. murotai has the following characters: clypeus with sparse, fine punctures; free margin of clypeus narrowly produced, with two triangular teeth medially, slightly emarginated in middle; labrum trapeziform; ventral surface of petiole with dense, sturdy, short, longitudinal carinae posteriorly; gena with fine punctures; parapsidal line distinct; pygidial area broadened U-shaped.
Female (Figs
Measurements. BL: 5.3 mm; HW : HLD : HLF = 81 : 53 : 53; HW : EWd : EW : TW : EL = 81 : 22 : 23 : 28 : 50; length of scape : length of pedicel : length of flagellomere I : width of flagellomere I : length of flagellomere II : width of flagellomere II = 28 : 8 : 8 : 3.5 : 9 : 4; PL : PW : LTI : WTI = 34 : 8 : 40 : 43.
Colour pattern. Clypeus dark brown apically; mandible yellowish except reddish brown apically; labrum, palpi, scape, tegula and pedicel fulvous; flagellomere I–VI segments fulvous, VII-X reddish brown to dark brown; pronotal lobe yellowish; forewing veins brown; legs fulvous except coxa dark brown basally; petiole black; metasoma black, last segment dark brown; setae on clypeus and mandible golden.
Head.
Mandible tridentate apically (Fig.
Stigmus fronticoncavus Bashir & Ma, sp. n. (female). a Frontal view of head b ventral view of mandible c dorsal view of head d dorsal view of collar e dorsal view of propodeum f dorsal view of petiole and gastral tergum I g lateral view of petiole and gastral tergum I h dorsal view of pygidial plate. Scale bars: 1 mm (a–h).
Mesosoma.
Anterior and lateral areas of pronotal collar with strong carinae, forming blunt angle at antero-lateral corner (Fig.
Legs. Normal, outer surface of hind tibia with three long, slender, fulvous to dark brown, spines.
Wings. Forewing venation typical for genus Stigmus, hindwing media diverging before cu-a.
Metasoma.
Dorsal surface of petiole subquadrate (cross section), slightly convex and widened toward apex distinctly, basal half of petiole with two sturdy lateral carinae and dense irregular rugae, apex with dense, sturdy, longitudinal carinae posteriorly (Fig.
Male. Unknown.
China (Yunnan).
The name, fronticoncavus, is derived from the Latin front- (= frons) and the Latin word concavus (= concave), referring to the hollow, deep and broad scapal.
Holotype ♀, China: Tibet: Linzhi, 29°42'N, 87°21'E, 20.VIII.2003, No. 20035170, coll. Dejimeiduo (ZJU); Paratypes: 2♀, same data as Holotype except No. 20035185, 20034328; 1♀, China: Tibet: Sejilashan Mount, 29°59'N, 94°54'E, 1.IX.2002, No. 20032992, coll. Naiquan Lin (ZJU).
Distinguished from closely related species S. japonicus by pronotal lobe white; median and upper frons with midsize punctures; vertex behind ocelli with midsize punctures; pygidial area half mat, apex truncate; lateral surface of petiole with two strong longitudinal carinae; mesoscutum with sparse large punctures; posterior surface of propodeum with a shallow somewhat narrow median groove, remaining with contiguous punctures and several oblique longitudinal rugae. Stigmus japonicus has following characters: pronotal lobe ivory; median and upper frons with fine punctures; vertex behind ocelli impunctate; pygidial area shiny, apex round; lateral surface of petiole with a few strong longitudinal carinae; mesoscutum with fine sparse punctures; posterior surface of propodeum with irregular rugae, groove inconspicuous.
Female (Figs
Measurements. BL: 4.3–4.8 mm; HW : HLD : HLF = 65 : 40 : 55; HW : EWd : EW : TW : EL = 65 : 14 : 18 : 21 : 42; length of scape : length of pedicel : length of flagellomere I : width of flagellomere I : length of flagellomere II : width of flagellomere II = 20 : 7 : 8 : 4 : 8 : 4.5; PL : PW : LTI : WTI = 34 : 9 : 34 : 36.
Colour pattern. Clypeus with reddish brown to dark brown band subapically; mandible ivory except reddish brown apically; palpi yellowish; scape beneath ivory, above dark brown largely; pedicel beneath fulvous, dark brown above; flagellomere dark brown to black; pronotal lobe white; tegula fulvous; forewing veins dark brown; fore and mid tibia, tarsi, femur (base and apex), trochanter, hind coxa, basal one third of hind tibia (remaining tibia dark brown) fulvous; petiole black; metasoma black except last segment reddish brown apically; setae on clypeus and mandible silvery.
Head.
Mandible tridentate apically (Fig.
Stigmus interruptus Bashir & Ma, sp. n. (female). a Frontal view of head b ventral view of mandible c dorsal view of head d dorsal view of collar e dorsal view of propodeum f dorsal view of petiole and gastral tergum I g dorsal view of pygidial plate h lateral view of petiole and gastral tergum I. Scale bars: 1 mm (a, c, e, f, h); 0.95 mm (b); 1.24 mm (d, g).
Mesosoma.
Anterior area of pronotal collar with sturdy carinae, incomplete, narrowly emarginated in middle, lateral carina lacking, without antero-lateral angle (Fig.
Legs. Normal, outer surface of hind tibia with three long, slender, fulvous to dark brown, spines.
Wings. Forewing venation typical for genus Stigmus, hindwing media diverging beyond cu-a.
Metasoma.
Dorsal surface of petiole subquadrate (cross section), strongly convex and widened toward apex slightly, and with two sturdy, longitudinal median carinae, and with irregular strong rugae anteriorly and medially (Fig.
Male. Unknown.
China (Tibet).
The name, interruptus, is derived from the Latin word interruptus (= interrupt), referring to the anterior area of the pronotal collar with sturdy carinae, incomplete, narrowly emarginate in the middle.
Holotype ♀, China: Yunnan: Xishuangbanna: Jinghong: Yexianggu, 22°09'N, 100°52'E, 23.IX.2006, coll. Hesheng Wang (YNAU); Paratypes: 1♀, China: Yunnan: Ruili: Nanjingli, 24°05'N, 97°47'E, 5.V.1981, coll. Fasheng Li (
Differs from S. pendulus by free margin of clypeus strongly produced and truncate medially, frontal furrow lacking, gena with large dense punctures, scutellum with several large punctures, pygidial area broadly triangular, with dense, slender, longitudinal striations; from S. munakatai Tsuneki it differs by setae on clypeus and mandible golden, upper frons with midsize to large punctures, inner orbital furrow broad, pronotal collar without antero-lateral angle, scutellum with large punctures, propodeum strongly reticulate, lateral surface with longitudinal rugae, pygidial area broadly triangular; in male, free margin of clypeus truncate medially, mandible reddish brown with black basally.
Female (Figs
Measurements. ♀ BL: 5.2–6.1 mm; HW : HLD : HLF = 84 : 45 : 70; HW : EWd : EW : TW : EL = 84 : 23 : 28 : 23 : 58; length of scape : length of pedicel : length of flagellomere I : width of flagellomere I : length of flagellomere II : width of flagellomere II = 25 : 8 : 7 : 4 : 7 : 5; PL : PW : LTI : WTI = 35 : 10 : 42 : 58. ♂, BL: 5.2–5.5 mm; HW : HLD : HLF = 81 : 41 : 63; HW : EWd : EW : TW : EL = 81 : 25 : 29 : 15 : 55; length of scape : length of pedicel : length of flagellomere I : width of flagellomere I : length of flagellomere II : width of flagellomere II = 20 : 8 : 6 : 3.5 : 6 : 4; PL : PW : LTI : WTI = 35 : 10 : 42 : 50.
Colour pattern. Clypeus black; mandible reddish brown to dark brown except black basally and apically; palpi dark brown; scape, pedicel, tegula and flagellomere dark brown to black; pronotal lobe black; forewing veins fulvous to dark brown; fore and mid legs: tibia, tarsi, femur (apex) reddish brown to dark brown, hind tarsus dark brown; petiole and metasoma black; setae on clypeus and mandible golden.
Head.
Mandible tridentate apically, median tooth larger (Fig.
Stigmus lobomelanicus Bashir & Ma, sp. n. (a–g female h–m male). a, h Frontal view of head b, i dorsal view of head c dorsal view of collar d dorsal view of propodeum e lateral view of petiole and gastral tergum I f dorsal view of petiole and gastral tergum I g dorsal view of pygidial plate j ventral view of gastral tergum VIII k dorsal view of male genitalia l lateral view of male genitalia m ventral view of male genitalia. Scale bars: 1 mm (a–f, h, i); 1.63 mm (g, j–m).
Mesosoma. Anterior and lateral areas of pronotal collar with strong carinae, without antero-lateral angle (Fig.
Legs. Normal, outer surface of hind tibia with three long, slender, fulvous to dark brown, spines.
Wings. Forewing venation typical for genus Stigmus, hindwing media diverging before cu-a.
Metasoma.
Dorsal surface of petiole subquadrate (cross section), moderately convex and widened toward apex distinctly, and with strong irregular rugae (Fig.
Male
(Figs
a Stigmus capoblongus Bashir & Ma, sp. n. (male) b, c Stigmus denticorneus Bashir & Ma, sp. n. (b female c male) d Stigmus fronticoncavus Bashir & Ma, sp. n. (female) e Stigmus interruptus Bashir & Ma, sp. n. (female) f, g Stigmus lobomelanicus Bashir & Ma, sp. n. (f female g male) a–g lateral view, Scale bars: 1 mm (a–g).
China (Yunnan, Guizhou).
The name, lobomelanicus, is derived from the Greek lob- (= lobe) and the Greek word melanicus (= black), referring to pronotal lobe black.
We are indebted to Dr. Xue-xin Chen (Zhejiang University, Hangzhou) and Dr. Wan-zhi Cai (China Agricultural University, Beijing) for providing specimens and Dr. Wojciech J. Pulawski for giving literatures. The authors thank three reviewers P. Girish Kumar, H. Dollfuss and M.V. Mokrousov for their informative critiques which helped the improvement of the manuscript. This study was funded by the National Natural Science Foundation of China (31750002, 31760641).