Pachyanthidium (Pachyanthidium) obscurum Pasteels

Eardley, Connal & Griswold, Terry, 2017, Taxonomic revision of the Afrotropical species of Pachyanthidium Friese (Hymenoptera: Megachilidae: Anthidiini), Zootaxa 4237 (3), pp. 401-453 : 443

Pachyanthidium (Pachyanthidium) obscurum Pasteels

( Figs 27–28 )

Pachyanthidium (Pachyanthidium) obscurum Pasteels, 1984: 148 , female holotype (NHML) Uganda.

Diagnosis. This species can be distinguished from all congeners except other members of the cordatum speciesgroup by the combination of naked eyes, arolia absent and metasomal dorsum considerably black. The female can be distinguished from these by the mandible not being spatulate, with five or six irregular more or less pointed teeth, mesosoma with light maculations restricted to the pronotal lobes, and all terga including T6 black centrally ( Fig. 27 ). The male is unknown but is expected to have similarly restricted mesosomal and metasomal maculations.

Description. FEMALE. Lengths: head 3.2 mm; scutum 2.4 mm; forewing 8.3 mm; body 8.4 mm. Integument largely black, without any red maculations, yellow maculations limited to small marks on clypeus, inner eye margin, preoccipital margin, pronotal lobes, medially, broadly interrupted lateral bands on T1–T5, T6 with or without small yellowish spot ( Fig. 27 ). Abundant erect pubescence about two ocellar diameters in length on face and mesosomal dorsum. Preoccipital ridge lamellate; eye naked; supraclypeus and clypeus distinctly bulging above paraocular area; clypeus with ventral edge straight, 2 pairs of submedial tubercles; mandible not spatulate, with 5-6 teeth, dorsal tooth small, acute; punctation of vertex and frons contiguous or nearly so, finer than punctures of scutum; pronotal lobe strongly lamellate; punctation of scutum and scutellum dense but not contiguous, more widely spaced posteromedially on scutum and medially on scutellum; omaulus lamellate; midventer of mesepisternum with anterior pit shallow; metepisternum without distinct spike overhanging posterior pit; forebasitarsus short and broad, length about 0.6x foretibia length, 3.3x its width; outer face of hind tibia not contiguously punctate; arolia absent; T1– T5 without lateral spines; T6 rather narrowly rounded posteriorly, laterally slightly lobate, without spine, sting emargination broadly V-shaped; scopa white.

MALE. Unknown.

Distribution. Pachyanthidium obscurum is only known from Uganda ( Fig. 28 ).

Material examined. Type material. Female holotype Pachyanthidium obscurum : ‘ HOLOTYPE, UGANDA: Ruwenzori Range. xii.1934 – i.1935. B.E. Afr. Exp. B.M. 1935–203, Namwamba Valley 6,500ft. F.W. Edwards, Type, B.M. TYPE HYM . 17a 3124, Pachyanthidium obscurum n.sp. J. Pasteels det., 1965’, NHML. Female paratype Pachyanthidium obscurum : ‘ UGANDA: Ruwenzori Range. xii.1934 – i.1935. B.E. Afr. Exp. B.M. 1935– 203, Nyamgasani Valley 8–9,000ft. C.R. Buxton, Paratype, Paratypus, COLL . MUS. TERVUREN don Dr J. Pasteels’, RMCA.

Figures

FIGURE 27. Female paratype of Pachyanthidium obscurum Pasteels. a. Face. b. Habitus. c. T 6. d. Lateral view.

FIGURE 28. Pachyanthidium obscurum Pasteels (●) and Pachyanthidium bicolor (Lepeletier) (*), known distribution.