Adoretus (Chaetadoretus) bjornstadi, Limbourg, 2016

Limbourg, Pol, 2016, Contribution to the knowledge of Afrotropical Rutelinae IV (Coleoptera: Scarabaeoidea: Melolonthidae), Belgian Journal of Entomology 38, pp. 1-42 : 1-42

Adoretus (Chaetadoretus) bjornstadi sp. nov.

( Figs 61-62, 65-66)

TYPE MATERIAL. Holotype ♂: [Coll. I.R.Sc.N.B., KENYA, Tsavo East N. P., Buchuma , 03.I.1983, Leg. A. Bjornstad] ( RBINS).

Paratypes: 1♂: [Coll. I.R.Sc. N.B., KENYA, S.E., Mackinon Road (A109), 14.IV.2004, Leg. M. Snizek] ( RBINS) ; 1♂, 1♀: [ KENYA: Southern shore of Lake Magadi, 2000ft, 1- 2.IV.1956, B. Verdcourt] [at light] [Brit. Mus. 1956-239] ( BMNH) ; 1♂: [ Oloitokitok (Nairobi), 30.XII.1965, arbocco] [Museo Civico di Genova] ( MCSN) ; 1♂: idem ( RBINS) .

DESCRIPTION

Male

Measurements and ratios ♂ (n = 3): LB: 12.5 – 13.5 mm, lB: 6 – 6.5 mm; LB/lB: 1.72; LP/lP: 0.50; LE/lE: 1.32.

Body: laterally slightly convex, relatively elongate, slightly bent, broader in middle of elytra; abdomen concave; process at base of prosternum rounded; entirely brownish-black, slightly shining.

Head: broad, clypeus rounded, entirely reflexed, clypeus and vertex totally covered with tubercles; frons unpunctuated; antennae 10-segmented, with club as long as flagellum.

Thorax: pronotum rectangular, broader than long; sides uniformly rounded from base to apex, with all margins carinate except middle of anterior margin; anterior angle slightly projecting and reaching posterior margin of eyes; strongly striated transversely.

Scutellum triangular with rounded sides and crescent shaped points.

Elytra: longer than broad; epipleura complete; costae obsolete; intervals with close crescent shaped points (only visible if setae missing); humeral calli marked; apical calli rounded and slightly projecting postero-ventrally.

Pygidium: laterally rounded, carinate along anal plate; not projecting postero-ventrally and not surpassing apex of elytra; transversely striated.

Legs: protibiae tridentate; pro-and mesotarsal larger claw cleft; metatarsus with larger claw twice longer than smaller and uncleft.

Hairs: upper and underside densely covered with short, decumbent white scales;

elytra with lines of small glabrous rounded zones with, in the middle of each, separated, erected, white or yellowish setae; long, erected yellowish-brown setae on all margins from canthus to apex of elytra, sparse on underside; erected white squamous setae on disc of pygidium.

Aedeagus: in lateral view, parameres elongate, dorso- and ventrally sinuate, apex pointed; in dorsal view, parameres laterally sinuate, strongly sinuate to apico-internal angle.

Female

Measurements and ratios ♀ (n = 1): LB: 13 mm, lB: 7 mm; LB/lB: 1.71; LP/lP: 0.51; LE/lE: 1.31.

Differs from ♂ by: laterally more convex and abdomen convex.

DERIVATIO NOMINIS. Dedicated to Mr Anders Bjørnstad (Skien, Norway) who collected the holotype .

DISTRIBUTION. Known from Kenya.

BIOLOGY. The species was collected in December, January and April. DIAGNOSIS. A. (Chaetadoretus) bjornstadi sp. nov. is extremely similar to A. (Chaetadoretus) hassoni Limbourg, 2011 but can be distinguished as follows: