Key to the species of Hesperopenna medvedevi group

1 Tibiae and tarsi black, elytra yellowish, glabrous. ......................................................... 2

– Legs completely brownish or orange, elytra brown, glabrous or partly covered with fine setae. ............................................................................................................................... 3

2 Antennae completely yellow. Extreme margin of epipleura in apical third yellow or at most brownish. Aedeagus ventrally with long thin incision placed on right side (Fig. 13). Female pygidium with apex distinctly pointed (Fig. 36). Laos, Thailand, Peninsular Malaysia. ................................................................................ H. tibialis (Kimoto, 1989)

– Antennae black with first two antennomeres pale. Extreme margin of epipleura in apical third black. Aedeagus ventrally with long thin incision placed medially (Fig. 18). Female pygidium with apex simply triangular (Fig. 40). Indonesia (Java, Bali). ......................... ............................................................................................................... H. zofka sp. nov.

3 Elytra glabrous. .............................................................................................................. 4

– Elytra densely covered with fine setae at least in apical half of elytra, .......................... 6

4 Last ventrite in male with subapical impression anteriorly surrounded with U-shaped ridge (Fig. 20). Aedeagus ventraly flat, with gradually tapering triangular apex (Fig. 12). Female pygidium with apex obtusangulate (Fig. 35). Vietnam, Laos, Thailand. .............. ............................................................................................ H. persimilis (Kimoto, 1989)

– Last ventrite in male without U-shaped ridge. Female pygidium with small U-shaped incision at apex (Fig. 38). ............................................................................................... 5

5 Aedeagus dorsally with two thin touching processes, ventrally with deep incision on left side, ventral surface not keeled in the middle (Fig. 15). North Myanmar. ....................... .......................................................................................................... H. bonifaci sp. nov.

– Aedeagus dorsally forms two wider touching processes, ventrally with deep incision on right side, ventral surface with high median keel (Fig. 16). Female pygidium with small U-shaped incision at apex (Fig. 38). South Myanmar. ....................... H. helferi sp. nov.

6 Elytra densely covered with fine setae only in apical half. ............................................ 7

– Elytra almost completely covered with fine setae (at least in apical two thirds). Aedeagus ventrally with deep U-shaped incision on right side (Fig. 14). Female pygidium with small semicircular incision at apex (Fig. 37). Laos, Thailand, China (Yunnan). ........................ ............................................................................................................ H. arnoldi sp. nov.

7 Aedeagus ventrally with symmetrical subtriangular apex, lateral incisions short and of the same depth, ventral surface flat with thin median keel (Fig. 11). Female pygidium with U-shaped incision and slightly concave posterior margins near incision (Fig. 37). Vietnam. ................................................................................... H. medvedevi nom. nov.

– Aedeagus ventrally asymmetrical, with very deep and wide subtriangular incision on right side, ventral surface with high median keel apically forming robust process bent downwards (Fig. 17). Female pygidium with deep U-shaped incision with oblique apical margins straight (Fig. 39). India (Meghalaya). ............................ H. sipekorum sp. nov.