Pachycerus (Faust, 1904)

Meregalli, Massimo, 2009, Revision of the Indo-African Pachycerus Schoenherr, 1823, with a description of four new species (Coleoptera: Curculionidae: Lixinae), Zoological Journal of the Linnean Society 157 (2), pp. 295-325 : 298

KEY TO THE INDO-AFRICAN SPECIES OF PACHYCERUS

1. Elytral scales simple, lanceolate, or aciculate. ........................................................................................ 2

– Elytral scales bifid, at least in apical half..............................................................................................5

2. Micropterous, scales round, very dense, whitish, completely covering integument. Length 10.6 mm. Somalia. ............................... Pachycerus somaliensis Meregalli, 2002 (see Meregalli, 2002 for the description and data)

– Macropterous, scales elliptical, not hiding integument on the whole surface.................................................3

3. Sides of pronotum widened anteriorly before apex and with a large, sharply conical tubercle at mid-length. Length: 7.0– 8.9 mm. Madagascar. .......................................................................................................... ............................................................................................................ Pachycerus badeni ( Faust, 1888)

– Sides of pronotum not widened anteriorly before apex, and with a small, scarcely prominent hump at mid-length........................................................................................................................................................4

4. Elytra with four very distinct round black spots, two near humeri and two on declivity; pronotum devoid of vestiture on disc; underside of rostrum with pentafid scales. Length: 12.0 mm (probably with rostrum). Yemen................ ....................................................................................................... Pachycerus efflatouni ( Tewfik, 1942)

– Elytra lacking distinct bare round spots on humeri and declivity; pronotum with vestiture of whitish scales on disc; underside of rostrum with bifid scales. Length: 7.5–10.4 mm. Sahel regions of Africa...................................... ............................................................................................................ Pachycerus sahelicus sp. nov.

5. Elytra with dense, long, erect setae, as long as the intervals, in several series on odd intervals, and in one series on even intervals. Length: 9.2–10.3 mm. Sudan; West Africa....................... Pachycerus vestitus Fåhraeus, 1842

– Elytra without setae or with short, moderately distinct setae....................................................................6

6. Elytra with short but distinct semi-erect setae; scales bifid, nearly from base. ............................................. 7

– Setae on elytra microscopic, indistinct or shorter than the scales; scales bifid, connected up to mid-length........8

7. Sides of vertex raised above eyes. Length: 5.9–8.7 mm. India, Pakistan, and Burma....................................... ............................................................................................................. Pachycerus sellatus Faust, 1904

– Sides of vertex not raised above eyes. Length: 10.4–14.3 mm. Southern Morocco. ........................................... ............................................................................................................. Pachycerus simonae sp. nov.

8. Head with raised tubercles above eyes; space between eyes smaller than rostrum at base..............................9

– Head smooth, lacking tubercles above eyes; space between eyes larger than rostrum at base. Length: 11.5 mm. Southern India. .................................................................................................................................. ............................................................................................................. Pachycerus barclayi sp. nov.

9. Apex of aedeagus subtruncate, lamella oval ( Fig. 28 ); cornu of spermatheca not acuminate; hemisternites broad ( Fig. 18 ); sides of pronotum converging forwards, dorsolateral impressions sharp, granules low, scarcely convex; length/width of elytra> 1.5. Length: 10.7–13.9 mm. Senegal, Mauritania, southern Morocco. ............................ ...................................................................................................... Pachycerus opimus ( Gyllenhal, 1834)

– Apex of aedeagus acute, lamella triangular ( Fig. 27 ); cornu of spermatheca narrowed at apex; hemisternites S-shaped, narrow ( Fig. 19 ); sides of pronotum parallel, dorsolateral impressions shallow; granules distinctly convex; length/width of elytra, 1.4. Length: 12.2–12.4 mm. Saudi Arabia, Egypt, and Sudan............................. ............................................................................................................... Pachycerus hippali sp. nov.

Figures

Figures 13–28. Pachycerus opimus (Gyllenhal, 1834), neotype female: antenna (16); detail of elytral scales (13); sternite VIII (15). Pachycerus opimus, Senegal, female: hemisternites (18); spermatheca (24). Pachycerus opimus, Senegal, male: aedeagus, dorsum, profile and lamella (22, 25, 28). Pachycerus hippali sp. nov., holotypus: antenna (17); detail of elytral scales (14); aedeagus, dorsum, profile and lamella (21, 26, 27). Pachycerus hippali sp. nov., Kordofan, paratypus female: sternite VIII (20); hemisternites (19); spermatheca (23). Scale bars: 15–17, 20–22, 25, 26, 1 mm; 18, 19, 0.5 mm; 23, 24, 27, 28, 0.2 mm.