Symmorphus (Symmorphus) cavatus Li & Chen

Li, Ting-jing & Chen, Bin, 2014, The taxonomic accounts of the genus Symmorphus Wesmael (Hymenoptera, Vespidae, Eumeninae) from China, with descriptions of three new species, ZooKeys 389, pp. 9-26 : 12-14

Symmorphus (Symmorphus) cavatus Li & Chen sp. n. Figs 11-16

Material examined.

Holotype. ♀, China, Yunnan Prov., Xishuangbanna, Jinghong City, Jinuo mountain, 22°02'17.81"N, 101°00'15.36"E, 901 m, 12.IV,2010, Rui Zhang, No. 1004037 (YNAU).

Description.

Female (Fig. 11): body length 6.5 mm, forewing length 7.0 mm. Black; with the following parts pale brown: basal transverse band of clypeus, post-ocular dot, medially uninterrupted dorsal pronotal band, large dorsal mesepisternal spot, tegula, large mesoscutellar spot apically, apex of T1, apical margin of both T2 and S2, apex of fore femur, and fore tibia largely; fore and mid tarsi dark brown. Wings lightly infuscate. Hairs pale brown, mesosoma without sparse lengthened hairs, in addition to short pubescence.

Head. Clypeus moderately punctate-puncticulate to foveolate-puncticulate, punctures sparse medioapically, space between punctures smooth and polish; clypeal apex truncated, clypeus evenly convex, without apical teeth (Fig. 12). Frons and vertex foveolate-puncticulate, major punctures closely spaced; interantennal carina prominent; cephalic fovea somewhat smaller than post ocellus, foveal interval subequal to postocellar distance, without cephalic foveal carina; occipital carina with 2 submedial incisions.

Mesosoma. Pronotum, except anterior face, foveolate-puncticulate, with major punctures closely spaced, more or less costate laterally; anterior face distinctly imbricate; pronotal carina dorsally obsolete; humeral angle slightly projected. Mesoscutum foveolate-puncticulate, major punctures closely spaced anteriorly and posteriorly, widely spaced laterally; notaulus complete; epicnemial carina complete; pseudosternum anterior margin without high reflexed margin. Mesoscutellum foveolate-puncticulate, major punctures closely spaced, with shallowly medial furrow. Mesepisternum with complete epicnemial carina (Fig. 15), dorsally punctate-puncticulate and minor punctures distinct basally, other parts foveolate-puncticulate, major punctures widely spaced, minor punctures obscure. Mesepimeron dull and densely striate. Metanotum primarily oblique and not vertical, dorsally dull, coarse and areolate-rugose. Propodeum dull, densely striate laterally, areolate-rugose dorsally, posterior face deeply heart-shaped hollowed, margin reflexed, complete and sharply defined throughout (Fig. 16), propodeal superior shelf short, 2 times trans-scutal sulcus; propodeal submedian carina entirely absent, propodeal valvula short posteriorly, fused distally to posterior margin; propodeal orifice small and indistinct.

Metasoma. Metasomal tergum 1 with postcarinal area foveolate-puncticulate, major punctures densely spaced, postcarinal length short, postcarinal length/apical width=0.68, carinal width/apical width=0.85, postcarinal sides barely convergent toward base, transverse carina complete, longitudinal furrow narrowly and shallowly depressed, with deeper narrow medial sulcus, apical margin indistinctly depressed (Fig. 14); S1 rugose anteriorly, basal carina inflated and raised posteriorly, fused to lateral oblique ridges, with median longitudinal ridge, lateral oblique ridges slightly prominent, median longitudinal ridge flanked by longitudinal carinate rugae; segment 2 foveolate-puncticulate, major punctures widely spaced from base to apex, minor punctures connected by obscure imbricate subsculpture; T3-T5 and S3 with densely foveolate toward apex; S3-S6 with imbricate subsculpture.

Male. Unknown.

Remarks.

This species is easily distinguished at once from all other species of Symmorphus by the combination of the following characters: propodeal posterior face deeply hollowed (Fig. 16), and occipital carina with 2 submedial incisions, in other species of the genus propodeal posterior face not hollowed.

Distribution.

China (Yunnan).

Etymology.

The specific name is the Latin cavatus (= hollow), which refers to propodeal posterior face of the species deeply hollowed.