Bruchidius ishwaensis ( Decelle, 1958 )

Delobel, Alex, Ru, Bruno Le, Genson, Gwenaëlle, Musyoka, Boaz K. & Kergoat, Gael J., 2015, Molecular phylogenetics, systematics and host-plant associations of the Bruchidius albosparsus (Fåhraeus) species group (Coleoptera, Chrysomelidae, Bruchinae) with the description of four new species, Zootaxa 3931 (4), pp. 451-482 : 468-470

Bruchidius ishwaensis ( Decelle, 1958)

Bruchus ishwaensis Decelle, 1958:82

Bruchidius ishwaensis ( Decelle): Decelle, 1979 :82

Material examined: Holotype (male) of Bruchus ishwaensis : Democratic Republic of Congo: “ Holotypus ”, “Genit ♂ / Br.57”, “Coll. Mus. Congo / Pl. d'Ischwa (Mahagi) / iii-1942 / J. Vrydagh”, “ Bruchus / ishwaensis n. sp. / det. J. Decelle 1958 ” [ MRAC].

Other material: Kenya: 9♂, 7♀, Garissa, 00°28’39’’S 39°33’00’’E, 292m, i.2002, ex Vachellia etbaica [1♂ 04903] (B. Le Ru) [ CBAD]; 1♂, 2♀, same data, ex V. reficiens [1♂ 0 2102, 1♀ 0 2202, specimen Ki11 used for DNA extraction] (B. Le Ru) [ CBAD, CBGP]; 16 ♂, 14 ♀, same data, ex V. zanzibarica [♂ 0 4602, 04702] (B. Le Ru) [ CBAD, CBGP]; 3♂, 2♀, Baringo, 00°35’10’’N 36°00’55’’E, 1084m, 18.vi.2007, ex V. reficiens (B. Le Ru) [ CBAD, CBGP]; 1♂, Kabarak, 00°10’26’’S 35°58’21’’E, 1910m, 18.vi.2007, ex V. seyal (B. Le Ru) [ CBAD, CBGP]; 3♂, 1♀, Voi (Tsavo), 11.iv.–14.iv.1997 (M. Halada) [ OLML]; 4♂, Voi (Tsavo), 23.iii. – 4.iv.1997, (M. Snizek) [ OLML]; 2♂, 1♀, same data, (M. Halada) [ OLML]; 1 ♂, Voi (Tsavo), 8 – 18.vi.1996, (M. Snizek) [ OLML]; 1 ♂, Tsavo W., Kitani Lodge, v. 2002 (A. Vojnits) [ HNHM].

A small to medium-sized (1.4–2.5 mm) brown and reddish species, with white, yellow and brown setation; antennae usually testaceous in male, or with median segments more or less darkened; female usually with antennal segments 6 (7, 8)–10 blackened, shorter and less eccentric than in male; on pronotum, basal lobes, median line and two lateral spots white, narrow apical stripe and postero-lateral impressions yellow; on elytra, dark specimens with brown heart-shaped sutural spot, absent in lighter specimens; usually 4 lines of brown spots: at base, first fourth (interstriae 3, 7, 9), middle (interstriae 5, 7, 8, 9), and apex almost entirely. Other distinctive morphological traits: antenna strongly serrate and eccentric in male, shorter and less eccentric in female; mucro of posterior tibia strong and elongated; absence of particular arrangement of setae on first ventrite in male, in female last visible tergite without impression or foveae.

Genitalia ( Figs. 20–21 ). Median lobe elongated, slender (w/l = 0.10–0.12), basal lobe small and circular, ventral valve narrow, acutely triangular; internal sac with 3 series of sclerites: a large, elongated, roof-like, dented sclerite, with blunt apex, followed by four globular and dentate sclerites (anterior pair with 2 to 4 teeth, posterior pair usually with single tooth), then a group of 1 to 4 slender spines; tegminal strut with large carina, parameres narrow and elongated, cleft to about 84% their length. In female, vagina short, without dorsal sclerite, spermathecal body pear-shaped ( Fig. 22 ).

Biology. Examined material reared from seeds of Vachellia etbaica , V. reficiens (Wawra) Kyal. & Boatwr., V. seyal and V. zanzibarica (S. Moore) Kyal. & Boatwr. Also reared from seeds of Vachellia drepanolobium (Harms ex Y. Sjöstedt) P.J.H. Hurter (as Acacia lathouwersi ) in the Democratic Republic of Congo by Decelle (1958), together with B. basilewskyi .

Discussion. Very closely related with B. saudicus Decelle from Saudi Arabia and Yemen ( Anton 2010); the two species differ in the shape of the large sclerite of the median lobe, and in the number of smaller sclerites, but both characters are highly variable in B. ishwaensis ; antennae are also shorter and stouter in B. ishwaensis . Differs from B. aurivillii in its longer and more serrate antenna.

Distribution. Democratic Republic of Congo, Kenya, and Somalia ( Decelle 1979).

Figures

FIGURES 20 – 24. Bruchidius ishwaensis (male): 20 — median lobe (ventral view); 21 — lateral lobes (ventral view); Bruchidius ishwaensis (female): 22 — spermatheca (lateral view); Bruchidius tanaensis (male): 23 — median lobe (ventral view); 24 — lateral lobes (ventral view).