Figures 7, 8
Material examined. Holotype: CHINA • ♀; Xinjiang, Aletai; 6.VII.1991; Deng-Yuan Wang leg.; No. 916308 (damaged: only one antenna left with apical segments missing, fore and middle legs on one side missing, and the metasoma disconnected from the mesosoma). Paratypes: CHINA • 3♂; Xinjiang, Eming; 14.VII.1990; Qi-Ma leg.; No. 907344, 907343, 907341 • 1♂, Xinjiang, Kuerle, 8.VII.1991; Jun-Hua He leg.; No. 913467.
Description. Body length 8.0 mm, fore wing length 5.3 mm.
Head. Antenna with at least 32 flagellomeres (but apical segments missing); first flagellomere ca 1.3× length of second flagellomere. Face punctate, interspaces of punctures less than their diameter. Clypeus punctate, interspaces of punctures 1.0–1.5× their diameter, slightly convex, apical margin slightly curved. Malar space weakly granulose, ca 0.5× basal width of mandible. Upper tooth of mandible as long as lower tooth, with a very weak lamella. Frons granulose, median carina absent. Vertex granulose. Interocellar distance 2.0× ocello-ocular distance and 1.9× distance between median and lateral ocelli. Temple mat, ca 0.5× as long as eyes in lateral view. Occipital carina evenly arched, reaching hypostomal carina above mandible base.
Mesosoma. Pronotum rugose-punctate, rugae stronger laterally. Mesoscutum granulose-punctate, with rugae on notaulic region. Scutellum punctate. Metanotum rugose. Mesopleuron punctate, transversely striate below tegula, speculum smooth and shiny, interspaces of punctures of lower half of mesopleuron 1.0–2.0× their diameter. Metapleuron punctate, interspaces of punctures narrower than on mesopleuron and less than their diameter, rugose-punctate ventrally. Propodeum with area basalis trapezoid; anterior transverse carina away from base; area superomedia combined with area petiolaris, transversely striate; area superomedia ca 0.6× as long as width of area petiolaris; area externa rugose-punctate; area dentipara strongly rugose; area lateralis rugose to rugose-punctate; costula, lateromedian longitudinal and lateral longitudinal carinae all strongly developed; propodeal spiracle oval, connected with pleural carina by a distinct carina.
Wing. Fore wing areolet present and with a short stalk emitting 2m-cu vein from its basal part. Marginal cell short, RS vein ca 2.0× longer than 2r&RS. Vein 1cu-a opposite of M&RS. External angles of second discal cell acute (80°). Hind wing with CU&cu-a reclivous, 2-CU not connected to CU&cu-a, not intercepted.
Legs. Hind femur 4.0× longer than wide. Inner spur of hind tibia ca 0.5× as long as first tarsomere of hind tarsus. Tarsal claws pectinate, hind tarsal claw with 3 slanting teeth basally, teeth short and small, ca 1.8× longer than arolium.
Metasoma. Surface somewhat coriaceous. First metasomal segment with dorso-lateral carina and lateral groove, suture separating first metasomal tergite from sternite ca 0.3 below mid height of petiole. First metasomal segment ca 2.5× length of width of postpetiole; petiole ca 1.5× longer than postpetiole. Second tergite ca 0.7× as long as first tergite, as long as its apical width; thyridium oval, its distance from basal margin of tergite ca equal to its length. Third tergite ca 0.9× as long as its apical width. Ovipositor sheath ca 1.4× longer than hind femur, ca 1.6× longer than first metasomal segment, and ca 0.9× as long as hind tibia. Ovipositor slightly upcurved, with depth at mid-length less than width of hind first tarsomere.
Colour. Black. Mandible medially and palpi, yellowish brown; tegula yellowish; scape and pedicel blackish brown; fore leg yellowish brown except coxa brown; mid leg yellowish brown except coxa and from first tarsomere 0.5 on blackish brown; hind leg yellowish brown except coxa, trochanter and from first tarsomere 0.2 on black; metasoma entirely black.
Male. Antenna with 36–39 flagellomeres, clypeus with more densely punctate than in female, interspaces of punctures as wide as diameter of punctures or narrower; frons with median carina developed; mesopleuron rugose above episternal scrobe; lower half of mesopleuron with punctures larger and denser, interspaces as wide as diameter of punctures or narrower; metapleuron with punctures not distinctly different from that on mesopleuron; antenna brown to blackish brown; fore and mid coxae at least apically yellow.
Comparison. This species is similar to S. amphipoeae Kusigemati, 1993, but differs from the latter by having first flagellomere ca 1.3× length of second flagellomere, frons granulose, pronotum rugose-punctate, propodeal area externa rugose-punctate, fore wing areolet with stalk short. S. amphipoeae: first flagellomere ca 0.7–0.8× length of second flagellomere, frons weakly and transversely striate, pronotum densely and weakly punctate, propodeal area external sparsely punctate, fore wing areolet small with a long stalk.
Etymology. Name derived from “petilus” (Latin for “thin”) and “dentis” (Latin for “tooth”), because its tooth is thin relative to other species in this genus.