Discoelius vasukii Pannure & Carpenter

Pannure, Arati, Belavadi, Vasuki V. & Carpenter, James M., 2017, A new species of the genus Discoelius Latreille, 1809 (Hymenoptera: Vespidae: Eumeninae) from India, Zootaxa 4272 (4), pp. 583-586 : 583-586

Discoelius vasukii Pannure & Carpenter , sp. nov. ( Figs 1–11 )

Material examined. Holotype, ♀, INDIA: Tamil Nadu, Coimbatore district, Valparai , 10°18'45"N, 76°52'29"E, 947 m, 5.vii.1982, coll. V.V. Belavadi [Department of Entomology, University of Agricultural Sciences, Gandhi Krishi Vignan Kendra, Bengaluru, India].

Description. Female. Body length (head+mesosoma+T1 and T2) 13.57 mm; forewing length 12.22 mm; head width 3.26 mm. Whole body with erect dense setae of various lengths (mostly on ventral portion of the body).

Head. Head as wide as high, strongly and rather densely punctate. Mandible stout, with four teeth and with several longitudinal carinae on upper portion. Clypeus 1.4 × wider than high, slightly convex with truncate anterior margin and straight basal margin and median basal carina connected with strong short vertical ‘Y’ shaped supraclypeal carina ( Fig. 3 ). Frons almost flat but weakly concave in middle. Both clypeus and frons striatopunctate. Ocular sinus with dense punctures and shiny. Vertex well developed and coarsely punctate. Gena well developed, sparsely punctate compared to vertex. Occipital carina weak/absent dorsally. Scape depressed with dense punctation, pedicel with minute punctation on basal half, shiny and impunctate on apical half. F1 little longer than F2; remaining flagellomeres wider than long with microscopic punctation.

Mesosoma. Length of mesosoma 1.6 × its width in dorsal view, and with coarse punctures, moderately shiny ( Fig. 1 ). Pronotal carina complete and raised. Anterior face of pronotum smooth and shiny except 1–2 dorsal rows of small punctures from which whitish setae arise. Dorsal and lateral surface of pronotum striatopunctate. Mesonotum with median longitudinal carina between notauli in anterior one-third of disc. Notauli well developed, especially wide and deep towards posterior portion of scutum, obscure and diverging near pronotum. Parapsidal lines weak, almost straight ( Fig. 4 ). Punctures on almost basal two-thirds of scutum dense and large, striatopunctate, one-third of area between notauli very minutely and sparsely punctured, posterior outside notauli with sparse punctures. Tegula much longer than broad with few scattered small punctures and with distinct emargination on its posterior inner margin where it adjoins parategula; posterior end much exceeding end of parategula; outer margin weakly rounded and posterior lobe narrowly defined ( Fig. 4 ). Scuto-scutellar suture crenate. Scutellum and metanotum each with an ill-defined median furrow and both irregularly punctate ( Fig. 5 ). Epicnemium with minute punctures. Mesopleuron dorsally striatopunctate, ventrally punctate. Metapleuron with fine longitudinal ridges ( Fig. 6 ). Propodeum less shiny, posterior surface rugosely striate to reticulate with distinct oblique ridges on upper dorsal portion; posterior face with high median carina running whole length of propodeum from short propodeal fovea ( Figs 5, 7 ); lateral face with superficial and irregular longitudinal ridges. Submarginal carina weakly produced, propodeal valvula and submarginal carina not free posteriorly ( Fig. 8 ). Forewing with SMC2 basally truncate. Prestigma of forewing almost absent, stigma roughly rectangular in shape. Mid tibia with two apical spurs.

Metasoma. T1 petiolate, 1.8–1.9 × as long as broad, posterior parts in dorsal view oval with subparallel lateral margins in posterior swollen part, and in profile, strong transverse depression just before apical margin (preapical furrow); coarsely punctate than remaining terga ( Figs 1 , 9 ). S1 almost impunctate and shining in basal narrow part, and coarsely punctate in apical wider portion. Length of T2 1.2–1.3 × its width, T2 with shallow and irregular punctures basally and remaining portion minutely punctate, punctures become sparser towards apical margin, interspaces between punctures 3–4 × that of puncture diameter ( Fig. 10 ). T2 with narrow median apical lamella. Subsequent terga with microscopic dense punctures in basal half and sparsely punctate in apical half without apical lamellae ( Fig. 11 ), apical margin of terminal metasoma triangular. S2 basally with irregular punctures, sparsely punctate over surface more sparser near middle portion. Subsequent sterna similar to terga, last sternum with very dense and minute punctures. Sterna without apical lamellae.

Colouration. Body completely black. Mandible, scape below in part, tegula and all legs especially tarsi, with brownish tinge.

Male. Unknown.

Remarks. The female of new species is distinguished from the similar Discoelius turneri ( Meade-Waldo, 1910) by the combination of the following characters: clypeus with straight basal margin (emarginate in D. turneri ); posterior face of propodeum strongly reticulate with a high median carina running whole length of propodeum from a short and nearly rounded propodeal fovea ( Fig. 5 ) (posterior face of propodeum weakly reticulate and propodeal fovea elongate in D. turneri ); T1 with strong macropunctures, not finely punctate ( Fig. 9 ); T2 with a narrow median apical lamella ( Fig. 10 ), subsequent terga without apical lamellae ( Fig. 11 ) (T2–T3 with well developed apical lamella, and T4 with apical lamella only at lateral corners in D. turneri ); two small round ferruginous spots on each side of pronotum absent (present in D. turneri ).

Distribution. India (Tamil Nadu).

Etymology. The species is named after its collector, Dr. Vasuki V. Belavadi.

Figures

FIGURES 1 – 4. Discoelius vasukii sp. nov., ♀, holotype. 1. Habitus, dorsal view; 2. Habitus, lateral view; 3. Head, frontal view; 4. Anterior portion of mesosoma, dorsal view.

FIGURES 5 – 11. Discoelius vasukii sp. nov., ♀, 5. Posterior portion of mesosoma; 6. Mesosoma, lateral view; 7. Posterior portion of propodeum; 8. Lower lateral portion of propodeum; 9. T 1, dorsal view; 10. T 2, dorsal view; 11. Posterior metasomal segments, dorsal view.