Bruchidius pluridentatus, Delobel, 2016

Delobel, Alex, 2016, Three newBruchidius species from Eastern and Southern Africa (Coleoptera: Chrysomelidae: Bruchinae), Acta Entomologica Musei Nationalis Pragae 56 (1), pp. 265-273 : 268-270

Bruchidius pluridentatus sp. nov.

( Figs 4–6 )

Type locality. Kenya, Taita-Taveta Co., Voi-Tsavo National Park.

Type material. HOLOTYPE: J (dissected [01814]), ‘ S.E. KENYA / Voi (Tsavo) 23.3- 4.4.1997 / leg. M. Snizek // Holotype // Bruchidius pluridentatus n. sp. / Delobel des. 2015’ ( OLML) .

Description. Length: 2.9 mm; width: 1.6 mm.

Body moderately stout, last visible tergite slanted about 10° from vertical. Integument reddish brown to black, with four anterior legs and antennae testaceous; pronotum dark brown, elytra reddish brown, more or less darkened at humerus, on sides and near apex; underside mostly black, but upper side of sternites and last ventrite testaceous. Vestiture well covering integument, particularly long and dense on pronotum, made of three-colored setae: whitish along pronotal mid-line, on interstriae 3 and 5, on underside and last visible tergite; yellowish on face, on rest of pronotum and interstriae 1, 2, 4 and 6; brown to black on isolated spot before apex of interstria 3, on humerus, on three spots on lateral sides of elytra (in basal fourth, at mid-length and near apex); apex of elytra with isolated brown spots.

Male. Head moderately elongated; eyes large, bulging, maximum head width 1.6 times width behind eyes; ocular sinus comparatively shallow; eyes separated by 0.29 times head width including eyes; face moderately wide, distance between posterior rim of eyes and apex of clypeus / distance between eyes = 2.46; eye moderately cleft, width at bottom of sinus composed of 6 ommatidia; post-ocular lobes narrow; front without carina, but with strong inter-ocular tubercle, shining; face with dense punctation, clypeus alutaceous. Antenna ( Fig. 6 ) reaching elytral humerus; antennal segments I–III cylindrical, segment IV widened at apex, subtriangular, segment V–X strongly serrate, XI oval (L/W = 1.7). Length of antennomeres: 1.4: 1.0: 1.0: 1.9: 2.6: 2.7: 2.8: 2.7: 2.6: 2.5: 3.8.

Pronotum trapezoidal, slightly campaniform, with maximum width at base (W/L = 1.2), its sides almost straight, not widened behind eyes; with shallow oblique impression on each side of basal lobe; disc strongly alutaceous, with dense punctation. Elytra 1.13 times longer than wide together, their sides widened in basal fourth, then almost parallel; disc slightly convex; two small teeth at base of striae 3 and 4, closer to each other than to elytron base; humeral callus moderately developed, alutaceous; striae narrow, interstriae flat, with dense micropunctation, possible alignment of larger punctures obscured by dense vestiture. Hind femur well incrassate, three times wider than median femur; mesoventral margin with small acute preapical denticle; ventral carina of hind tibia complete, lateral and dorsomesal not reaching base; apex with mucro slightly shorter than tarsomere I width, lateral denticle about one-third mucro length, wider but hardly longer than dorsal denticles.

Abdomen with ventrite V strongly emarginated, medially almost entirely concealed under ventrite IV; ventrite I without particular arrangement of setae. Last visible tergite shield-shaped, 1.1 times longer than wide, with apex strongly turned under.

Genitalia. Median lobe ( Fig. 4 ) moderately elongated (maximum width excluding basal strut / total length = 0.155), widened apically; basal hood narrow, not notched posteriorly; ventral valve narrowly subtriangular, its apex acute, with a median group of 8 setae; hinge sclerites absent; proximal part of internal sac densely lined with hyaline lamellae, followed by a number of large sclerites: first an ovoid burr-like mass, then four large curved thorns; median part of the sac smooth, with 13 curved spines and four pointed rods; distal bulb densely lined with minute needles that are rear facing in anterior part, and forward facing in apical third. Basal strut narrow, subtriangular, with large dorsal keel; lateral lobes almost entirely divided (cleft to about 95% their length); apex of parameres slightly widened, with about 20 setae each ( Fig. 5 ).

Female. Unknown

Differential diagnosis. The shape of the aedeagus is similar to that found in several members of the B. albosparsus species group. One of these, B. ishwaensis (Decelle, 1958) also shows small thorn-like sclerites in the internal sac, but it lacks the other types of sclerites (ovoid and rod-like). The peculiar ovoid burr-like sclerite is made up of numerous agglomerated teeth, quite distinct from other compound sclerites found in various members of the same species group, such as B. aurivillii (Blanc, 1889) and B. elnairensis (Pic, 1931) . Rod- or hair-like sclerites of B. pluridentatus are similar to those found in B. glomeratus Delobel, 2015 , but similar sclerites may also be found outside the B. albosparsus group, e.g., in some specimens of B. ituriensis (Decelle, 1958) and B. snizeki Delobel, Anton, Le Ru & Kergoat, 2013 , which are both members of the Bruchidius ituriensis species group ( DELOBEL et al. 2013).

Host plants. Unknown.

Etymology. The specific epithet (masculine adjective) pluridentatus (= more-teethed), refers to the different sizes and shapes of sclerites in the internal sac.

Distribution. Kenya (Taita-Taveta County).

Figures

Figs 1–6. Genitalia and antenna of Bruchidius species:1–3 – B. nataensis sp. nov. (1 – median lobe; 2 – lateral lobes; 3 – male antenna). 4–6 – B. pluridentatus sp. nov. (4 – median lobe; 5 – lateral lobes; 6 – male antenna).