Bruchidius horridus, Delobel & Ru, 2015

Delobel, Alex & Ru, Bruno Le, 2015, New Bruchidius species reared from Vachellia (Fabaceae: Mimosoideae: Acacieae) seeds from Eastern and Southern Africa (Coleoptera: Chrysomelidae: Bruchinae), Acta Entomologica Musei Nationalis Pragae 55 (1), pp. 261-272 : 262-265

Bruchidius horridus sp. nov.

( Figs 1 , 6–9 )

Type locality. Kenya, Gasissa Co., Garissa, 00°28.651′S, 39°33.392′E, 249 m a.s.l.

Type material. HOLOTYPE: J (dissected), ‘ KENYA, Garissa (249 m) / ex Acacia horrida pods / 00°28.651’S 39°33,392’E / janvier 2003, B. Le Ru coll. // Holotype // Bruchidius horridus n. sp., / Delobel & Le Ru des. 2015’ ( MNHN) . PARATYPES: 9 JJ 9 ♀♀ (2 JJ 1 ♀ dissected), same data as holotype ( MNHN, CBGP).

Description. Length: 1.6–3.0 mm; width: 1.0– 1.7 mm.

Body moderately stout, last visible tergite slanted about 20° from vertical. Integument light to dark reddish brown, antennae and four anterior legs testaceous, posterior legs reddish brown,

last abdominal sternites usually testaceous; last tarsomeres and antennomeres 8–10 darkened; last visible tergite testaceous in male, apical two-thirds black in female. Vestiture made of scaly, fulvous setae, with white markings: longitudinal line becoming thinner anteriorly and two small dots on pronotum, irregular and incomplete transversal stripes on elytra, basal half of third interval, interrupted by small brown dot; last visible tergite almost uniformly white in male, in female with long white setae converging towards elevated midline; underside vestiture white.

Male. Head short, eyes strongly bulging, maximum head width about 1.6 times width behind eyes; eyes separated by 0.25 times head width including eyes; face wide, with distance between posterior rim of eyes and apex of clypeus / distance between eyes = 2.2; eye moderately cleft, width at bottom of sinus composed of 7 ommatidia; no defined carina on frons but strong and shiny bulge posteriorly. Punctation of face small and dense. Antenna ( Fig. 6 ) short, measuring 0.25 times body length; antennal segments 1–4 submoniliform, 5 and following slightly widened apically, strongly eccentric, transverse, 11 apically rounded, 1.7 times longer than wide. Lengths of antennomeres: 1.5: 1.0: 0.8: 0.6: 1.2: 1.2: 1.3: 1.1: 1.2: 1.0: 2.0.

Pronotum trapezoidal, at base wider than long (W/L = 1.4), its sides slightly convex medially; oblique impression on sides of basal lobe strong; its disc with strong and dense punctation, punctures small and regular. Elytra evenly convex, basally not wider than pronotal base, together as long as their combined width, maximum width near middle; dented elevation at base of striae 3 and 4, teeth closer to each other than to elytron base; humeral callus well developed; striae very narrow and shallow; interstriae wide and flat, strongly alutaceous. Hind femur moderately incrassated, twice wider than median femur; mesoventral margin with small acute preapical denticle; hind tibia apically strongly widened, with ventral carina complete, lateral and dorsomesal strong but not reaching base; apex of tibia with mucro as long as tarsomere 1 width, lateral denticle about half mucro length. First tarsomere ventrally with small acute denticle.

Abdomen with ventrite 5 moderately emarginated, its length medially about half as long as sternite 4; ventrite 1 with small patch of dense setae at basal angle. Last visible tergite subcircular in dorsal aspect, only slightly longer than wide, with apex moderately turned under.

Genitalia. Median lobe ( Fig. 7 ) of moderate length, slender (maximum width excluding basal hood / total length = 0.13), subcylindrical, poorly sclerotized; basal hood sub-circular, not notched apically; ventral valve subtriangular, short and wide, with tip acute and bearing numerous sensillae, and two lateral groups of 4 setae; dorsal valve braced with sclerotized ring; no hinge sclerites; internal sac elongated, lined in basal three-fifths with blunt, transparent transverse tubercles, then dorsally cluster of short acute denticles, and ventrally larger, more sclerotized, longitudinally notched, blunt villi; apical bulb densely lined with very fine needles, gonopore large, circular. Basal strut ( Fig. 8 ) with short obsolete dorsal keel; lateral lobes slender, cleft 80 % their length, pubescent; apex of parameres with a small number of setae, one of them much longer.

Female. Similar to male, last visible tergite less convex basally, but with strongly bulging longitudinal keel in apical third; disc black; ventrite 5 about as long as ventrite 4. Genitalia: ovipositor long, vagina linear and membranous, without sclerite, with 30–40 transparent spines at entrance of bursa copulatrix; spermathecal body ( Fig. 9 ) small, ovoid, unwrinkled, with apical diverticulum thin, unevenly curved, about three times longer than body, with blunt tip; spermathecal duct opening not protruding, distinct from lateral gland duct opening. Differential diagnosis. Even though all examined specimens lack the black sutural dot, typical for the B. albosparsus species group, the habitus of B. horridus sp. nov. corresponds with the morphology of the group. The internal sac is devoid of strong spines and sclerites, but these are also absent in several other members of the group, like B. albosparsus (Fåhraeus, 1839) , B. tanaensis (Pic, 1923) , B. grandemaculatus (Pic, 1933) , or B. nongoniermai Delobel, 2007 according to DELOBEL et al. (2015). A bulging pygidium in female is also present in B. grandemaculatus . The presence of a small patch of modified setae at the basal angle of male first ventrite is a neutral argument because it is commonly found outside the B. albosparsus group (see e.g. ANTON 1998) as well as within the group. The peculiar crenellated villi present in the distal part of the internal sac constitute a morphological trait that distinguishes the new species from all species known to us.

Host plants. Larvae develop in seeds of Vachellia horrida (L.) Willd., a species closely related to South African V. karroo Hayne , but distinct from it according to ILDIS (2014).

Etymology. The specific epithet (masculine) is the Latin adjective for ‘bristly’, a reference to the peculiar ornamentation of the internal sac, and to the host plant name as well.

Distribution. Kenya (Garissa County).

Figures

Figs 1–5. Habitus of Bruchidius species. 1 – B. horridus sp. nov., J paratype. 2 – B. quadrispinosus sp. nov., J holotype. 3 – B. quadrispinosus sp. nov.,♀ paratype. 4 – B. spathiger sp. nov.,J paratype (Kenya). 5 – B. tumidulus sp. nov., J paratype (Kenya, Kampi Ya Moto).

Figs 6–12. Genitalia and antenna of Bruchidius species. 6–9 – B. horridus sp. nov. (6 – male antenna; 7 – median lobe; 8 – lateral lobes; 9 – spermatheca). 10–12 – B. quadrispinosus sp. nov. (10 – male antenna; 11 – median lobe; 12 – lateral lobes).