Stigmus lobomelanicus Bashir & Ma

Bashir, Nawaz Haider, Li, Qiang & Ma, Li, 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, pp. 51-69 : 64-67

Stigmus lobomelanicus Bashir & Ma sp. n. Figs 5, 6f, g

Type material.

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 (CAU); 1♂, China: Yunnan: Ruili, 23°59'N, 97°37'E, 2.V.1981, No. 812489, coll. Junhua He (CAU); 1♂, China: Yunnan: Mengla: Wangtianshu Forest Park, 22°01'N, 100°47'E, 2.V.2005, coll. Peng Wang (YNAU); 1♀1♂, China: Guizhou: Luodian, 25°13'N, 105°50'E, 2-5.VI.1981, coll. Fasheng Li (CAU); 1♀, China: Yunnan: Menghai, 22°27'N, 98°20'E, 17.V.1981, coll. Fasheng Li (CAU).

Diagnosis.

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.

Description.

Female (Figs 5 a–g, 6f):

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. 5a). Clypeus shiny, with sparse fine to midsize punctures, apex with a line, large dense punctures, strongly reflected toward apex gradually, setae on clypeus sparse, long; free margin of clypeus strongly produced and truncate medially (Fig. 5a). Scapal hollow half mat, slenderly coriaceous, somewhat shallow, without tubercle medially. Frontal furrow lacking. Median frons half mat, somewhat coriaceous, upper frons with midsize to large, sparse punctures, slightly convex. Ocellar triangle area flat, shiny, impunctate, near eyes area with dense, short, impressed lines, opaque area smaller than hind ocellus. Vertex behind ocelli shiny, with fine sparse punctures, round posteriorly; gena shiny, with sparse midsize to large punctures (Fig. 5b); ventral gena shiny, with large dense punctures mixed with several irregular rugae laterally. Head from above with temples rarely convergent posteriorly, subquadrate. Occipital carina incomplete, not ending in hypostomal carina, extending to nearly base of mandible, not tooth, outer orbital furrow much narrowed, no crenulate, on lower part somewhat broad, coarsely crenulate. Inner orbital furrow broad, shiny, slenderly rugulose; outer orbital furrow lacking.

Mesosoma. Anterior and lateral areas of pronotal collar with strong carinae, without antero-lateral angle (Fig. 5c). Mesoscutum shiny, with midsize to large punctures, anterior area slenderly coriaceous. Admedian line weakly impressed, extending to one third of scutum. Prescutal sutures deeply grooved and crenulate, reaching only anterior of scutum. Parapsidal line weakly impressed. Scutellum mat, coriaceous, with several large punctures. Metanotum distinctly rugulose. Mesopleuron shiny, with sparse large punctures, posterior mesopleuron with sparse, short, sturdy, longitudinal rugae, episcrobal area with dense reticulation, scrobal suture, omaulus and hypersternaulus much broadened, distinctly crenate, scrobal suture complete. Propodeal enclosure triangular medially, and with sturdy irregular reticulation (Fig. 5d). Posterior surface of propodeum with a fairly broadened shallow median groove, and sparse sturdy transverse rugae in groove, remaining sturdy, irregularly reticulate (Fig. 5d). Lateral surface of propodeum with dense, sturdy, oblique longitudinal rugae anteriorly and medially, and irregular reticulation posteriorly.

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. 5f); lateral surface of petiole shiny, with several irregular rugae and two strong lateral carinae medially and posteriorly (Fig. 5e); ventral surface of petiole with 4 sturdy, short, longitudinal carinae posteriorly. Metasomal segments shiny, with fine sparse punctures, gastral sternum VI with fine or coarse punctures, half mat; pygidial area shiny, broadly triangular, with dense, slender, longitudinal striations (Fig. 5g).

Male (Figs 5 h–m, 6g). Almost same to female except mandible reddish brown with black basally, setae on clypeus dense, silvery and short; mandible bidentate api cally (Fig. 5h); clypeus moderately reflected toward apex gradually, with dense fine punctures (Fig. 5h); vertex behind ocelli impunctate (Fig. 5i); gena shiny, inconspicuous coriaceous, with several large punctures dorsally, ventral gena shiny, with sturdy, sparse, irregular rugae laterally; head from above with temples distinctly convergent posteriorly; flagellomeres without tyloids, normal; dorsal surface of petiole subquadrate (cross section), slightly convex and widened toward apex slightly, and with strong irregular rugae; metasomal segments shiny, nearly impunctate. Sternum VIII (Fig. 5j). Male genitalia (Fig. 5 k–m).

Distribution.

China (Yunnan, Guizhou).

Etymology.

The name, lobomelanicus, is derived from the Greek lob- (= lobe) and the Greek word melanicus (= black), referring to pronotal lobe black.