Tachysphex oxychelus Pulawski ex Krombein & Pulawski 1994

Tachysphex oxychelus Pulawski

NAME DERIVATION.—Oxychelus is an adjective based on the Greek words oxys, sharp, and chele, a claw; with reference to the acute female claws.

DIAGNOSIS.—The female of oxychelus has distinctive claws: instead of being evenly curved, the claws are somewhat expanded dorsally near the midlength and have a straight, thin apical portion (Figure 70). In addition, the mesopleuron is conspicuously microsculptured and shallowly punctate, erect setae of the head and thorax are straight, and the clypeal lip is emarginate mesally (Figures 59, 61). Similar claws are found in many mediterraneus (which also occurs in Sri Lanka), but in that species the mesopleuron is rugose, erect setae of the head and thorax are sinuous, and the clypeal lip is obtusely dentate mesally (Figures 72, 74).

The male of oxychelus can be recognized by the finely, densely punctate sterna II–VI combined with a dull mesopleuron and apically tridentate sternum VIII (Figure 64), although in some specimens the apex of sternum VIII is not tridentate but has a broad median lobe; and subsidiary recognition features are: propodeal setae slightly inclined posterad (essentially erect), and apical tarsomeres with subapical spines on venter.

DESCRIPTION.—Vertex punctures varying from less than one to several diameters apart. Scutal punctures one diameter apart or less. Mesopleuron dull, strongly microsculptured, with shallow punctures that average about one diameter apart. Propodeal dorsum irregularly ridged, side ridged. Hindcoxal dorsum: inner margin obtusely angulate basally. Sternum I apicomesally with small, shallow depression.

Setae erect on vertex, about one midocellar diameter long; slightly inclined posterad on scutal disk, about one midocellar diameter long; nearly erect along hypostomal carina, about 0.3 × basal mandibular width; inclined posterad on propodeal dorsum except a few anteromedian setae inclined anterad.

Body black except mandible reddish mesally; humeral plate yellowish anteriorly, dark brown posteriorly. Terga I–III silvery fasciate apically. Humeral plate of forewing dark brown mesally, yellow laterally. Wings hyaline. Frontal and clypeal vestiture silvery.

.—Labrum emarginate. Clypeus (Figures 59, 61): bevel varying from shorter than basomedian area to markedly longer mesally; lip emarginate mesally, with two lateral incisions on each side. Vertex width 0.9–1.1 × length. Dorsal length of flagellomere I 1.5 × apical width. Forefemoral venter shiny, with microscopically fine punctures that are several to many diameters apart. Outer surface of foretibia with a few erect, thin bristles but without spines. Forebasitarsus with 10 or 11 rake spines. Hindtarsomere IV: length equal to apical width; emargination weakly acute, almost rectangular (Figure 67); apicoventral margin barely concave, practically straight. Apical tarsomere: apicoventral margin gently arcuate but not expanded into lobe (Figure 69); lateral margin with small spines at about midlength; venter with single median spine on posterior half. Claws somewhat expanded dorsally near midlength, with straight, thin apical half (Figure 70). Pygidial plate shiny, without microsculpture, sparsely punctate (Figure 63). Length 6.8–7.5 mm.

.—Clypeus (Figures 60, 62): bevel ill defined; lip broadened mesally, free margin obtusely angulate to slightly arcuate; distance between lip corners 0.8–0.9 × distance between corner and orbit. Vertex width 1.1–1.2 × length. Dorsal length of flagellomere I 1.2–1.4 × apical width. Bottom of forefemoral notch shiny, glabrous. Outer margin of forebasitarsus without preapical spines. Venter of apical tarsomeres with subapical spines (Figure 68). Punctures of tergum VII about one diameter apart. Stema uniformly, densely and minutely punctate. Apical margin of sternum VIII tridentate or with broadly rounded lobe (Figure 64). Volsella: Figure 65. Penis valve: Figure 66. Length 4.8–6.0 mm.

Sternal setae appressed.

COLLECTING PERIOD.—January through May, 24–26 September.

HABITAT.—This abundant species is widespread in the Dry Zone at low elevations with average annual rainfall of 1700 mm or less, and it was collected once in the Wet Zone at sea level (Figure 71).

GEOGRAPHIC DISTRIBUTION.—Sri Lanka.

RECORDS.—Holotype: , Sri Lanka, Mannar District, Kondachchi, Silavathurai, PBK, TW, MJ, GR (USNM).

Paratypes: SRI LANKA: ANURADHAPURA DISTRICT: Nochchiyagama, R.T. Simon Thomas (1, ITZA). COLOMBO DISTRICT: Pamunugama, KVK, TW, LW (3, USNM). HAMBANTOTA DISTRICT: Palatupana, KVK, PBK, PF, EGD (3, 2, USNM); Palatupana tank, KVK, TW, LW (1, USNM). MANNAR DISTRICT: 0.5 mi (0.8 km) NE Kokmotte Bungalow in Wilpattu National Park, KVK, PBK, SK, DWB (5, USNM); same locality, KVK, TW, SS, TG (3, USNM); Kondachchi, PBK, TW, MJ, GR (8, CAS; 18, 3, USNM); Kondachchi, Ma Villu, KVK, LW, PL (2, USNM); Kondachchi, Ma Villu, [PBK] (13, 3, NMC); Kondachchi, Silavathurai, PBK, TW, MJ, GR (10, 6, CAS; 47, 10, USNM), [PBK] (9, NMC); Mannar, PBK, TW, MJ, GR (1, USNM); Ma Villu, KVK, TW, SS, TG (10, CAS; 3, 20, USNM); Marichchukkaddi, PBK, TW, MJ, GR (1, USNM), [PBK] (2, 4, NMC); Silavathurai (5, NMC). MONARAGALA DISTRICT: Angunakolapelessa, KVK, TW, LJ, VK (2, USNM); Mau Ara, 10 mi (16 km) E Uda Walawe, KVK, PBK, TW, MJ (1, USNM). TRINCOMALEE DISTRICT: China Bay, KVK, PF, DWB, VG (1, USNM); 7 mi (11.2 km) W Trincomalee, KVK, PBK, SK, DWB (1 USNM). VAVUNIYA DISTRICT: Parayanalankulam, D. Davis and W. Rowe (2, USNM), KVK, LW, PL (1, USNM).