Stigmus interruptus 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 : 61-64

Stigmus interruptus Bashir & Ma sp. n. Figs 4, 6e

Type material.

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).

Diagnosis.

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.

Description.

Female (Figs 4, 6e):

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. 4a), median tooth larger (Fig. 4b). Clypeus shiny, flat, with sparse, midsize punctures, setae on clypeus sparse, long; free margin of clypeus narrowly produced and with two triangular teeth medially, slightly reflected (Fig. 4a). Scapal hollow shiny, somewhat shallow, broadened, not well outlined, without tubercle medially. Frontal furrow very fine and weakly impressed, inconspicuous. Median and upper frons shiny, with midsize sparse punctures, gently convex. Ocellar triangle area flat, shiny, impunctate, near eyes area with dense, short, impressed lines, opaque area large. Vertex behind ocelli shiny, with several midsize punctures (Fig. 4c). Gena shiny, with sparse, midsize to large punctures dorsally, ventral gena shiny and smooth. Head from above with temples somewhat roundly 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.

Mesosoma. Anterior area of pronotal collar with sturdy carinae, incomplete, narrowly emarginated in middle, lateral carina lacking, without antero-lateral angle (Fig. 4d). Mesoscutum half mat, with sparse large punctures, anterior and posterior areas with dense, longitudinal micro-sculptures. Admedian line distinct, extending to half of mesoscutum. Prescutal sutures deeply grooved and crenulate, reaching half of mesoscutum. Parapsidal line distinct. Scutellum shiny, with fine sparse punctures. Metanotum slenderly coriaceous. Mesopleuron shiny, smooth, episcrobal area with dense, slender, longitudinal rugae, scrobal suture, omaulus and hypersternaulus nar rowed, distinctly crenate, scrobal suture complete. Propodeal enclosure elongate, U-shaped medially, and with a sturdy longitudinal median rugae and sparse irregular transvers rugae (Fig. 4e), lateral area with contiguous irregular rugae mixed with sparse, slender, oblique longitudinal rugae, laterally. Posterior surface of propodeum with somewhat narrow median groove, shiny, with several transverse rugae, remaining with contiguous punctures and several oblique longitudinal rugae (Fig. 4e); lateral surface of propodeum with contiguous punctures and slender mixed with several sturdy, oblique longitudinal rugae.

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. 4f); lateral surface of petiole with a few strong longitudinal carinae medianly and posteriorly (Fig. 4h); ventral surface of petiole with a few strong longitudinal carinae medianly and posteriorly. Metasomal segments shiny, nearly impunctate, gastral sternum VI with fine or coarse punctures, half mat; pygidial area half mat, broadly U-shaped, apex truncate, with longitudinal micro-sculptures, basal area with several large punctures (Fig. 4g).

Male. Unknown.

Distribution.

China (Tibet).

Etymology.

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.