Bruchidius elnairensis ( Pic, 1931 )

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 : 460-465

Bruchidius elnairensis ( Pic, 1931)

Bruchus elnairensis Pic, 1931:35

Bruchidius voltaicus Decelle , nomen nudum: Nongonierma, 1978, Varaigne-Labeyrie & Labeyrie, 1981 Bruchidius acaciaephilus Anton, 2000:246 (synonymy in Anton & Delobel, 2003:171)

Material examined. Kenya: 13♂, 12♀, Kabarnet, 00°28’14’’, 35°51’07’’E, 1365m, 18.vi.2007, ii.2003, ex Vachellia dolichocephala [2♂ 0 1614, 0 1714, specimen E11 used for DNA extraction] (B. Le Ru) [ CBAD, CBGP]; other material as listed in Anton & Delobel (2003), including specimens from Burkina-Faso, Ghana, Saudi Arabia and Sudan.

A medium-sized (2.0– 2.5 mm) species, with brown red integument and darkened areas; basal antennal segments and legs yellowish, apical antennal segments red-brown. Vestiture dense, with denser yellowish to white setae: sides of pronotum, meso- and metasternites, a small triangle at base of last visible tergite; pronotal disc with ill-defined median longitudinal yellowish-whitish band, sometimes with small white spot on each side of it; elytra often with oblong yellowish, whitish and brownish marks, with two irregular transverse whitish bands and striking longitudinal whitish mark in middle of interval 3, sometimes elytra predominantly yellowish with indistinct paler spots; last visible tergite whitish with two basal yellowish spots. Ventrite 1 with small baso-central patch of semierect thin setae. In female, last visible tergite with pair of deep foveae with shiny margin and setous central area. Genitalia ( Figs. 5–6 ). Median lobe of moderate length (w/l = 0.13); ventral valve subtriangular, with semicircular row of about eight setae in basal half and acute apical tip; internal sac with subapical median longitudinal agglomeration of about twelve large blunt denticles, at mid part with paired oblique, apically combined agglomerations of eight moderate, sharp denticles each, basally followed by paired oval agglomerations of about 20 small needles each ( Fig. 5 ). Lateral lobes simple, cleft to half their length, with about eight setae at apex; tegminal strut moderate, with short median carina. In female, vagina long and membranous, without dorsal sclerite.

Biology. Examined material reared from Vachellia dolichocephala (Harms) Kyal. & Boatwr. Also recorded from seeds of V. amythethophylla (Steud. ex A. Rich.) Kyal. & Boatwr. , V. hockii (De Wild.) Seigler & Ebinger , V. flava (Forssk.) Kyal. & Boatwr. , V. gerrardii , V. s e ya l and V. seyal var. fistula (Schweinf.) Kyal. & Boatwr.

Discussion. Bruchidius elnairensis is distinguished from the closely related B. aurivillii by having vestiture predominantly yellowish, last visible tergite broader, paired foveae near apex of female last visible tergite, paired and only apically combined agglomerations of denticles in mid part of internal sac, larger paired agglomeration of higher number of needles in basal part of internal sac, lateral lobes slimmer and less separated.

Distribution. Burkina Faso, Ghana, Kenya, Saudi Arabia, Senegal ( Anton & Delobel 2003), and Sudan ( Pic 1931).

Bruchidius eminingensis Delobel , sp. nov.

Material examined. Holotype (male) of Bruchidius eminingensis : Kenya: “ Kenya, Emining / Acacia seyal seyal / S 00°17’52’’ E 35°55’17’’, 1384m, / 18 juin 2007 / B. LeRu coll.” “genitalia: lame Delobel 17607” “ Bruchidius eminingensis n.sp., Delobel des., 2014”[ MNHN]. Paratypes: 3♂ 5♀, same data as holotype [1♀, 17507, specimen GK101 used for DNA extraction] [ CBGP].

Other material. Kenya: 3♂, Machakos, S 01°50’09’’ E 37°26’24’’, 1665m, 23.i.2008, ex Vachellia seyal [3♂ 0 8108, 0 8408, 11208] (B. Le Ru) [ CBGP, MNHN].

Description. Length (pronotum-last visible tergite): 2.2–2.4 mm; width: 1.0– 1.1 mm. Body oval, stout, about half as deep as long, last visible tergite slanted about 10° from vertical, slightly turned under in apical one-fourth. Body yellowish brown to reddish brown, underside and face black; antenna and four anterior legs light testaceous, posterior legs somewhat darker, last tarsal segments black; disc of last visible tergite more or less blackened. Vestiture dense but not completely hiding integument, made of slightly scaly white, yellowish and brown setae; pronotum disc mainly brown, with large white prescutellar spot, scutellum white; elytra mainly yellowish, in holotype with brown oval spot between basal and apical thirds of elytral suture and interstriae 1–3, absent in light specimens; small dark spots in basal fourth of interstria 3, in interstriae 7 and 9, at apex of intervals 2, 4–5, and 7–9; last visible tergite densely and almost uniformly whitish.

Male. Head short, eyes widely separated, bulging, maximum head width 1.46 times width behind eyes; eyes separated by 0.32 times head width including eyes; face wide, distance between posterior rim of eyes and apex of clypeus / minimum distance between eyes = 2.2; width at bottom of sinus composed of 5–6 ommatidia; interocular carina blunt, ending basally in a bare tubercle. Antenna measuring one-fourth body length; segments 1–4 moniliform, 5 wider than long, following ones transverse, moderately eccentric, 11 rounded apically (l/w = 1.1); length of antennomeres: 1.1; 1.0; 1.1; 0.7; 0.8; 0.9; 1.0; 0.9; 1.0; 1.1; 1.8.

Pronotum subcampaniform, wider at base than long (w/l = 1.3) its sides slightly convex medially; disc with small, dense punctures.

Elytra oval, regularly widened beyond humerus, widest before middle, 1.1 times longer than combined width; two strong teeth at base of interstria 4; striae thin and sharp, interstriae flat, shining.

Hind femur incrassated, 1.8 times wider than mid femur, mesoventral margin without preapical tooth; hind tibia strongly widened apically, with mucro two thirds width of first tarsomere; lateral denticle about half mucro length, and dorsal denticles about half the latter.

Abdomen with ventrite 5 moderately emarginated, ventrite 4 shorter medially than laterally, base of ventrite 1 with a large circular impression bearing short, dense setae; last visible abdominal tergite shield-shaped, only slightly longer than wide (l/w = 1.04).

Genitalia ( Figs. 7–8 ): Median lobe stout (maximum width excluding basal hood/ total length = 0.17), ventral valve subtriangular, moderately sclerotized, with rounded tip, bearing on each side 2–4 setae; basal one-fourth of internal sac densely lined with round denticles, middle of sac smooth, apical part with large dorsal pouch densely lined with short and elongated spines. Basal strut elongated, subtriangular, without keel, lateral lobes as long as basal strut, cleft to 65% their length; apex of parameres with eight long setae.

Female similar to male, last visible tergite reddish with disc black, regularly convex, setation yellowish, denser on basal and apical triangles, also along more or less distinct mid-line; spermatheca comma-shaped, with smooth surface, without visible vaginal sclerite.

Biology. Both series were reared from Vachellia seyal seeds.

Discussion. Bruchidius eminingensis is most similar to B. nongoniermai Delobel , from which it is separated on the basis of details of aedeagus shape and ornamentation: B. nongoniermai ( Figs. 9–10 ) has a more slender median lobe, with saccus devoid of translucent tubercles in anterior part, but completely lined with minute needles. It can be further distinguished by body color and ecology: B. nongoniermai is a light yellowish species that feeds in Vachellia kirkii (Oliv.) Kyal. & Boatwr. seeds. This species of acacia is restricted to the sahelian zone ( Chad, Mali, Sudan) ( Delobel 2007). Several undescribed species with similar external morphology exist in the Southeastern part of Africa; they cannot be distinguished from one another without a careful examination of genital morphology.

Etymology. Named after the locus typicus, the town of Emining in Kenya.

Distribution. Kenya.

Bruchidius gerrardiicola Delobel , sp. nov.

Material examined. Holotype (male) of Bruchidius gerrardiicola : Kenya: “ Kenya, Gilgil / Acacia gerrardii 2036m / S 00°23’45’’ E 36°18’45’’ / 29 octobre 2007 / B. LeRu coll.” “genitalia: lame Delobel 06508” “ Bruchidius gerrardiicola sp. nov., Delobel des, 2014” [ MNHN]. Paratypes: 10♂ 10♀, same data as holotype, [1♀, 0 7108, specimen GK881 used for DNA extraction] (B. Le Ru) [ CBGP].

Other material: Kenya: 2♂ 4♀, Emining, S 00°17’52’’ E 35°55’17’’, 1384m, 18.vi;2007, ex Vachellia seyal [2♂, 17007, 17407, specimen GK 100 used for DNA extraction] (B. Le Ru) [ CBGP, MNHN]; 1♂, SE Kenya, Voi (Tsavo), 11.iv.–14.iv.1997 (M. Halada) [ OLML]; 1♂, same data but 23.iii.–4.iv.1997 (M. Halada) [ OLML].

Length (pronotum-last visible tergite): 2.2–2.4 mm; width: 1.3–1.4 mm. Body oval, stout, about half as deep as long, last visible tergite slanted about 20° from vertical, humped and turned under in apical one-fourth. Body dark brown, lighter on elytral disc and apex; basal five to seven antennal segments and four anterior legs testaceous, posterior legs reddish-brown with extreme base blackened; last antennal segment black or reddish brown, last tarsal segments black. Vestiture dense but not completely hiding integument, made of slightly scaly white, yellowish and black setae; pronotum disc variegated, with dark and white areas, and a median longitudinal white line; a black oval spot between basal third and apical fourth of elytral suture, on interstriae 1–3; interstriae 4, 6, 8 yellowish, 3, 5, 7, 9 with alternating white and dark spots; a wide strand of dense white setation along side, from behind eye to upper part of ventrites; last visible tergite whitish, with denser setation along midline, especially at base.

Male. Head short, eyes widely separated, bulging, maximum head width about 1.44 times width behind eyes; eyes separated by 0.32 times head width including eyes; face wide, distance between posterior rim of eyes and apex of clypeus / minimum distance between eyes = 2.2; width at bottom of sinus composed of 6–7 ommatidia; interocular carina well defined, disc of clypeus with large, isolated punctures. Antenna measuring one-third body length; segments 1–4 moniliform, 5 as wide as long, following ones transverse, moderately eccentric, 11 rounded apically (l/w = 1.2); length of antennomeres: 2.3; 1.0; 1.4; 1.6; 1.8; 1.6; 1.7; 1.6; 1.6; 1.8; 2.8.

Pronotum subcampaniform, wider at base than long (w/l = 1.4) its sides slightly convex medially; disc with small, dense punctures.

Elytra oval, regularly widened beyond humerus, widest near middle, about as long as combined width; two small teeth at base of striae 3 and 4; odd interstriae distinctly wider than even interstriae, striae thin and sharp, interstriae flat, shining.

Hind femur incrassated, 2.4 times wider than mid femur, mesoventral margin with minute preapical tooth; hind tibia strongly widened apically, with mucro as long as width of first tarsomere; lateral denticle about half mucro length, and dorsal denticles about half the latter.

Abdomen with ventrite 5 slightly emarginated, ventrite 4 about as long medially as laterally, ventrite 1 with a round spot of thin white erect setae at base; last visible abdominal tergite subcircular, only slightly longer than wide (l/w = 1.06), disc with large, partly coalescent punctures.

Genitalia ( Figs. 11–12 ). Median lobe moderately stout (maximum width excluding basal hood/ total length = 0.15), ventral valve ogival, well sclerotized, with acute tip, bearing on each side 3–4 setae; basal one-fourth of internal sac smooth, middle of sac with two rows of more than 20 closely packed, slender, thorn-like sclerites and two lateral groups of 3–4 spines, apical part of sac with a small batch of minute translucent granulation. Basal strut without keel, lateral lobes slightly shorter than basal strut, cleft about three-fourths their length; apex of parameres with seven long setae.

Biology. Larvae were reared from seeds of two Vachellia species: V. gerrardii and V. seyal .

Discussion. Bruchidius gerrardiicola is most similar to B. glomeratus n. sp., from which it is separated on the basis of aedeagus ornamentation: in addition to the median strand of densely packed spines, B glomeratus shows a few slender spines in distal position; these additional spines are also present here, but are more numerous and in medial position. The saccus of B. gerrardiicola also lacks the sclerotized plates present in B. glomeratus . In females, the last visible tergite is less markedly bulging than in B. glomeratus .

Etymology. From the name of one of the identified host plant, Vachellia gerrardii . Distribution. Kenya.

Bruchidius glomeratus Delobel , sp. nov.

Bruchidius sp. KE05: Kergoat et al., 2005, 2007, 2008

Material examined. Holotype (male) of Bruchidius glomeratus : Kenya: “ Kenya, Kangonoi / 1°06’20’’S 37°41’51’’E, 1850m / i.2002, ex graines Acacia etbaica / B. Le Ru coll.“, “ Bruchidius glomeratus sp. nov. / A. Delobel des. 2014”, “ Holotype ”. Paratypes, 3♂, 8♀, same data as holotype [1♂, slide 0 2502, two females dissected, genitalia in glycerin, specimen Kc11 used for DNA extraction] [ CBGP, MNHN].

Description. Length (pronotum-last visible tergite): 2.1–2.2 mm; width: 1.3 mm.

Body stout, last visible tergite slanted about 10° from vertical, humped and turned under in apical one-fourth. Body reddish-brown, except center of sternites and claws, darker; antennal base and four anterior legs testaceous, posterior legs reddish-brown; antennae progressively blackened from segment 5 or 6, segment 11 lighter than preceding ones. Vestiture not completely hiding integument, made of short and thin, dull white setae, almost uniform, except for large dark rhomboid spot along posterior part of elytral suture and interstriae 2–3; additional more or less inconspicuous brownish spots at basal fourth of interstria 3 and middle of interstriae 9–10; a wide strand of dense white setation along side, from behind eye to upper part of ventrites; last visible tergite whitish, with denser setation along midline, especially at base.

Male. Head short, eyes widely separated, bulging, maximum head width about 1.36 times width behind eyes; eyes separated by 0.29 times head width including eyes; face wide, distance between posterior rim of eyes and apex of clypeus / minimum distance between eyes = 2.1; width at bottom of sinus composed of 6–7 ommatidia; no interocular carina, but a small shining bulge. Antenna about one fourth body length; segments 1–4 moniliform, 5 as wide as long, following ones transverse, almost symmetrical, 11 rounded apically (l/w = 1.0); length of antennomeres: 1.4; 1.0; 0.9; 0.9; 1.1; 1.0; 1.0; 1.0; 1.0; 1.1; 1.6.

Pronotum subcampaniform, wider at base than long (w/l = 1.3) its sides slightly convex medially; disc with small, dense punctures.

Elytra not wider at base than pronotum, but regularly widened beyond humerus, widest near middle, 1.1 times longer than combined width; two small teeth at base of interstria 4; striae on disc thin and sharp, interstriae flat, shining.

Hind femora moderately incrassated, mesoventral margin with minute preapical tooth; hind tibia strongly widened apically, with mucro shorter than width of first tarsomere; lateral denticle about 2/3 mucro length, and dorsal denticles about half the latter.

Abdomen with ventrite 5 deeply emarginated, ventrite 4 very short medially, ventrite 1 with a small round spot of erect setae at basal 0.4 of segment; last visible abdominal subcircular, only slightly longer than wide, disc with large, partly coalescent punctures.

Genitalia ( Figs. 13–14 ). Median lobe moderately stout (maximum width excluding basal hood/ total length = 0.14), ventral valve ogival, moderately sclerotized, with acute tip, bearing on each side 4 setae; basal one-fourth of internal sac smooth, middle of sac with two rows of about 17 closely packed, slender, thorn-like sclerites, saccus with four slender spines and a pair of lightly sclerotized structures. Basal strut elongated, slender, with inconspicuous keel, lateral lobes shorter than basal strut, cleft to about three-fourths their length; apex of parameres with four long setae and three shorter ones.

Female. Similar to male, but antennae shorter, last visible tergite not turned under, reddish brown, with sharp apical bulge surrounded by black, flattened circular area, base of tergite with white triangle; sternite 5 about twice longer than sternite 4.

Biology. Larvae were reared from seeds of Vachellia etbaica (Schweinf.) Kyal. & Boatwr. , an East-African species restricted to Somali-Masai woodland ( ILDIS, 2014).

Discussion. Bruchidius glomeratus is morphologically most similar to B. basilewskyi (Decelle) and B. gerrardiicola n. sp. In B. basilewskyi , the pronotum is more transverse and strongly bulging laterally, its posterior legs are almost entirely black, as is its last visible tergite; the arrangement of large spines in the internal sac ( Fig.

15) is quite similar with that of B. glomeratus ( Fig. 13 ), but it lacks the four additional elongated spines in the posterior area. Bruchidius glomeratus can be also separated from B. gerrardiicola by the shape of the black elytral spot (rhomboid in B. glomeratus , subcircular in B. gerrardiicola ). It has also close morphological affinities with B. grandemaculatus (Pic) , a usually larger species with body colour darker and antenna light brown. Male genitalia of the three species show a very close relationship, with an arrangement of spines that is also met in species with “eyed” female last visible tergite ( Anton & Delobel, 2003), particularly in B. elnairensis ; male genitalia in B. grandemaculatus are of a quite different type. In female, last visible tergite is less bulging than in B. grandemaculatus , but more than in B. gerrardiicola .

Etymology. Past participle (masculine) of Latin verb glomerare, “to group”, referring to the dense longitudinal grouping of spines in the median part of the internal sac.

Distribution. Kenya.

Figures

FIGURES 5 – 8. Bruchidius elnairensis (male): 5 — median lobe (ventral view); 6 — lateral lobes (ventral view); Bruchidius eminingensis (male): 7 — median lobe (ventral view); 8 — lateral lobes (ventral view).

FIGURES 9 – 12. Bruchidius nongoniermai (male): 9 — median lobe (ventral view); 10 — lateral lobes (ventral view); Bruchidius gerrardiicola (male): 11 — median lobe (ventral view); 12 — lateral lobes (ventral view).

FIGURES 13 – 15. Bruchidius glomeratus (male): 13 — median lobe (ventral view); 14 — lateral lobes (ventral view); Bruchidius basilewskyi (male, paratype, MNHN): 15 — median lobe (ventral view).