Stigmus capoblongus 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 : 55-56

Stigmus capoblongus Bashir & Ma sp. n. Figs 1, 6a

Type material.

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).

Diagnosis.

Differs from S. japonicus Tsuneki (1954) by frontal furrow weakly impressed, inconspicuously; median and upper frons with fine sparse punctures; admedian line weakly impressed; lateral surface of propodeum shiny and smooth anteriorly and medially, distinctly coriaceous mixed with several longitudinal rugae posteriorly. Closely related to S. quadriceps Tsuneki but differs by free margin of clypeus with two triangular teeth medially; flagellomere beneath fulvous, above, remaining reddish brown to dark brown; scutellum shiny, with fine sparse punctures; petiole subquadrate (non-cylindrical); pronotal collar with strong carinae anteriorly, lateral carina lacking, without antero-lateral corner.

Description.

Male (Figs 1, 6a):

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. 1a). Clypeus nearly flat, with dense tiny punctures, setae on clypeus dense, short; free margin of clypeus slightly produced and with two triangular teeth medially, slightly reflected (Fig. 1a). Scapal hollow half mat, coriaceous, somewhat shallow, provided with a vestigial minute tubercle medially, not spined. Frontal furrow very fine and weakly impressed, inconspicuously, sometimes lacking. Median and upper frons shiny, with fine sparse punctures, gently convex. Ocellar triangle area flat, shiny, impunctate, area near eyes with dense, short, impressed lines, opaque area smaller than hind ocellus. Basal half of vertex shiny, with sparse fine punctures, posterior area half mat, with inconspicuous microsculpture and fine sparse punctures (Fig. 1b). Gena shiny, with several fine punctures dorsally, ventral gena shiny and smooth. Head from above with temples slightly convergent posteriorly. Occipital carina incomplete, not ending in hypostomal carina, suddenly ended at the posterior ridge of stomal hollow, not tooth, much narrowed, no crenulate; inner and outer orbital furrows lacking; flagellomeres without tyloids, normal.

Mesosoma. Pronotal collar with strong carinae anteriorly, lateral carina lacking, without antero-lateral corner (Fig. 1c). Mesoscutum shiny, with several fine punctures, anterior area with dense large punctures medially; admedian line weakly impressed, extending to half of scutum. Prescutal sutures deeply grooved and crenulate, reaching one third of scutum. Parapsidal line distinct. Scutellum shiny, with fine sparse punctures. Metanotum slenderly coriaceous. Mesopleuron shiny, with tiny, sparse or dense punctures, posterior mesopleuron with sparse, short, sturdy, longitudinal rugae, episcrobal area with dense, fairly slender, longitudinal rugae, scrobal suture, omaulus and hypersternaulus broadened, distinctly crenate, scrobal suture complete. Propodeal enclosure U-shaped medially, and with a sturdy, longitudinal median carina and sparse transvers rugae, with several sturdy, oblique longitudinal rugae laterally (Fig. 1d). Posterior surface of propodeum with irregular rugae, groove inconspicuous. Lateral surface of propodeum shiny and smooth anteriorly and medially, distinctly coriaceous mixed with several longitudinal rugae 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 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. 1e). Lateral surface of petiole with a few strong longitudinal carinae (Fig. 1f). Ventral surface of petiole with 4 sturdy, short, longitudinal carinae posteriorly. Gaster segments shiny, nearly impunctate. Male genitalia (Fig. 1 g–i).

Female. Unknown.

Distribution.

China (Gansu, Shanxi).

Etymology.

The specific name, capoblongus, is derived from the Latin cap- (= head) and the Latin word oblongus (= oblong), referring to the oblong head.