Key to Ethiopian Plinthisus Species­Groups

1. Scent gland auricle curving or pointing caudad (Figs. 18–21, 23, 26); auricle sometimes expanded distad into a tear­drop shape (Fig. 21)................................................. 2

— Scent gland auricle recurved, first curving caudad then cephalad. (Figs. 22, 24–25, 27); auricle apex, if expanded, scimitar­shaped (Figs. 24–25) ..................................... 8

2. Pronotum with at least posterior lobe heavily punctate (Figs. 1–2); brachypter coleopteroid, hemelytra extending caudad to at least tergum 5 (Fig. 2) ....................... 3

— Entire pronotum appearing impunctate, with no more than micropunctures on posteriorlobe;brachypterwithhemelytratruncate,extendingonlytoabdominaltergum4(Fig. 5) ....................................................................................................................................... 7

3. Male profemur with one row of 2–3 spines (Fig. 115); less than 1.8 mm in body length ......................................................................................................... Pulchellus Group

— Male profemur with two rows of many spines, inner row with at least 2 major spines (Figs. 110–113); more than 2.2 mm in body length ..................................................... 4

4. Bucculae very large, much wider than width of labium and extending anteriorad beyond tylus (Fig. 8); brachypter without fringe of membrane on hemelytron, abdominal tergal sutures 4–5 and 5–6 transverse, not curving caudad, tergum 6 greater in length than either tergum 4 or 5 (Fig. 39) ........................................ Rudebecki Group

— Bucculae not wider than width of labium, not extending anteriorad beyond tylus (Figs. 9–10), brachypter with fringe of membrane on hemelytron (Fig. 2); abdominal tergal sutures 4–5 and 5–6 curving caudad, tergum 6 much shorter than either tergum 4 or 5, (Fig. 40–41)................................................................................................................... 5

5. Entire dorsum, pleura, and abdominal venter coarsely and evenly punctate; eyes either greatly foreshortened, more than twice as high as long, or very small, eye width 1/6 of interocular space Brachyoccus Group

— Anterior lobe of pronotum, proepisternum and abdominal venter impunctate to finely punctate, much less punctate than posterior lobe of pronotum; eye normal, less than twice as high as long or, width greater than 1/4 interocular width ............................... 6

6. Sparsely clothed above with short sericeous decumbent hairs, body hairs shorter than antennal hairs and less than width of metatibia; in brachypter, male protibia (Fig. 110) lightly curved, armed beneath only with small tubercles of equal size........................... .......................................................................................................... Tineoides Group

— Densely clothed above with long upright hairs, hairs longer than antennal hairs and twice width of metatibia; male protibia (Fig. 113) strongly curved, armed beneath with mixed large and small tubercles .......................................................... Hirsutus Group

7. Body nearly glabrous, with at most very short decumbent hairs (Fig. 5); profemur mutic, convex below (Fig. 117) Fynbosi Group

— Body densely clothed with long semi­erect hairs; profemur (Fig. 120) flattened and sulcate beneath, armed with a single spine ...................................... Zuurbergi Group

8. Scent gland auricle strongly recurved, reaching anterodorsal corner of granulose scent area, dividing scent gland area (Figs. 24–25); over 1.9 mm in length .......................... 9

— Scent gland auricle with only apex curved cephalad, not dividing the granulose scent area (Figs. 22, 27); under 1.8 mm in length ................................................................ 10

9. Dorsal body surface granulose­pebbled in texture (Fig. 6); profemur convex beneath (Fig. 118) ........................................................................................ Peninsularis Group

— Dorsal body surface polished, shining in texture (Fig. 7); profemur flattened and sulcate beneath (Fig. 119) ....................................................................... Lamprus Group

10. Head, pronotum, scutellum and hemelytra coarsely and densely punctate­granulose (Figs. 3–4), no trichobothriumlike seta on eye (Fig. 12) ........................ Ericae Group

— Head, pronotum, scutellum and hemelytra smooth, lightly punctate with well­separated punctures, eye with a long trichobothriumlike seta............................................ 11

11. Lateral margins of hemelytra ecarinate; brachypterous hemelytron with posterior margin transversely truncate, without membrane, barely reaching 4th abdominal tergum; body densely pilose above .................................................. Drakensbergensis Group

— Lateral margin of hemelytra carinate; brachypterous hemelytron with posterior margin oblique, with fringe of membrane, and reaching at least 5th abdominal tergum; body sparsely clothed with short decumbent sericeous hairs above ........... Ptilioides Group