Bruchidius tricolor, Anton & Delobel, 2017

Anton, Klaus-Werner & Delobel, Alex, 2017, Three new Asian species of Bruchidius (Coleoptera: Chrysomelidae: Bruchinae), Acta Entomologica Musei Nationalis Pragae 57 (1), pp. 161-172 : 165-168

Bruchidius tricolor sp. nov.

( Figs 8–13 , 22 )

Type locality. Laos, Louangphrabang Province, 5 km W of Ban Song Cha, 20°33–34′N, 102°14′E, 1200 m a.s.l.

Type material. HOLOTYPE: ♂ (dissected), ‘ LAOS, 1.-16.v.1999 / Louangphrabang pr. / 20°33-4’N 102°14’E / Ban Song Cha (5km W), / 1200 m, Vit. Kubán leg.’, genitalia slide ‘ Bruchidius / 26 09 99 I’ ( NHMB). PARATYPES: 2 ♀♀, ‘NW THAILAND 1-8.v. / MAE HONG SON 1992 / BAN SI LANG 1200 m / J.HORAK LEG.’ ( CKWA) ; 1 ♀, ‘NE INDIA: ASSAM; / 5km N of Umrongsor, 700 m; / 25°27’N 92°43’E; 21.v.1999 / Dembický & Pacholátko leg.’ ( NHMB); 1 ♀. ‘ THAILAND, / Prov. Nan, / above Mae / Charim waterfall, // 6.xi.2004, / M. Földvári, / A. Orosz, L. Papp’; 1 ♀, same data but 7-8.xi; 1 ♀, THAILAND, / Prov. Nan, / Nam Mae Charim Road , 20 th km // secondary bamboo / forest, 6.xi.2004, / M. Földvári, / A. Orosz, L. Papp’ ( HNHM) .

Additional material examined. ♂ (dissected), ‘ INDIA, U.P. 1978, W. Wittmer / Bhimtal 1.-15.5 / 1400-1500 m’, genitalia slide ‘ Bruchidius / 23.10.00V’ ( CKWA).

Description. Length: 1.6–1.8 mm, width: 1.1–1.2 mm.

Body stout and thick, last visible tergite vertical. Integument colour reddish-brown; meso- and metathorax, abdominal ventrite I, hind femora excluding apex and elytra excluding apex black; tip of antennomere XI more or less darkened; antenna, front and mid legs yellowish- -brown. Vestiture moderately dense, not completely covering body, made by long and thin, homogeneously greyish setae on head, elytra, complete ventral body and rarely last visible tergite, distinctly denser setae completely covering body on scutellum; longer, homogeneously pale yellowish-brown setae on pronotum and often last visible tergite, denser and silky setae on prescutellar area of pronotum.

Male. Head moderately elongated, eyes bulging, maximum head width about 1.5 times width behind eyes; eyes separated by 0.16 times head width including eyes; face short and narrow, with distance between posterior rim of eye and apex of clypeus / distance between eyes = 4.5; eye cleft to less than half of its diameter, width at bottom of sinus composed of about 7 ommatidia; carina on frons well developed, shining, ending basally in blunt tubercle. Punctuation of face fine and dense, vanishing to extreme apex of clypeus. Antenna ( Fig. 8 ) long, reaching end of basal third of elytra; antennomeres oblong, I–IV cylindrical, V–X with parallel sides and scarcely subserrate, length of antennomeres: 1.8: 1.0: 1.2: 1.3: 1.5: 1.6: 1.6: 1.4: 1.3: 1.2: 2.0.

Pronotum campaniform, greatest width at base (W/L = 1.3), with sides moderately bisinuate; disc mediolaterally faintly bulging, with small oblique impression on side of basal lobe; punctuation dense, punctures strong, irregular and ocellate on disc.

Elytra 1.13 times as long as their combined width, widest at end of basal third; sides subparallel in mid third; scutellar area faintly depressed, scarcely visible protuberance with two small teeth at base of striae 3–4, their distance to elytral base scarcely larger than distance between teeth; striae on disc deep and sharp, with strong punctures; interstriae flat, with dense micropunctation and irregularly dispersed, coarse punctures.

Hind femora incrassate, at their widest 2.4 times as wide as mid femora; mesoventral margin with strong, oblong preapical denticle, ventrolateral margin strongly sinuate opposite denticle. Hind tibiae continuously arched and widened from base to apex, 2.5 times wider at apex than width at base, with dorsomesal, ventral and lateroventral margins complete, lateral margin strong but not reaching to base; apex of tibia with mucro about twice longer than width of tarsomere I at base; lateral denticle slim and acute, about 1/3 mucro length; dorsally series of three minute denticles. Tarsomere I ventrally with blunt denticle.

Abdomen with ventrite V emarginate, medially turned out, its length medially as long as ventrite IV; ventrite I basomedially without particular arrangement of denser setae. Last visible tergite subtriangular, regularly arched, about 1.1 times as long as wide at base, with apex not turned under, briefly truncated.

Genitalia. Median lobe ( Fig. 9 ) elongate (maximum width excluding basal hood / total length = 0.10), sides parallel, briefly narrowed before apex; basal hood of moderate size, subcircular, not emarginated; ventral valve subcircular, produced apically as thin and recurved beak, base convex, in mid with transverse and arched row of five setae; dorsal valve braced with strongly sclerotized, large ring; no hinge sclerites, but instead the wall of internal sac bears two dense groups of long and acute bristles, emerging as fringe between ventral and dorsal valves; wall of internal sac with hyaline scales; basal part of saccus lined with multifid scales, followed by sclerotized needles and one large, elongated, moderately sclerotized sclerite with about 18 teeth; gonopore wide and circular, surrounded by minute hyaline needles; spiculum gastrale long, slender, Y-shaped. Basal strut ( Fig. 10 ) with barely visible trace of keel; lateral lobes cleft to about 2/3 their length; apex of parameres with 4–5 long setae, modified with conical flap and internal projection.

Female. Similar to male, antenna about ¼ shorter; pygidium subvertical and less arched; ventrite V about twice as long as IV. Genitalia ( Fig. 11 ): vagina membranous, bursa copulatrix with oblong, faintly sclerotized sclerite bearing lateral series of about nine teeth; ovipositor short, with moderately long and flattened spiculum gastrale; segment IX short and wide, longitudinal apodemes distinctly arched; spermathecal body oblong-ovoid, with apical diverticulum drawn out and evenly curved.

Differential diagnosis. Habitus, size and genital morphology indicate that the new species is a member of the B. japonicus species-group. Its reddish-brown colour, yellowish-grey vestiture on pronotum and greyish-white elytral pattern are characteristic; a single male from Uttar Pradesh showing an elytral pattern similar to B. nepalensis , though less striking (on each elytron two large dark brown areas, one basal and one lateral, beyond middle) belongs to the same species but was excluded from the list of paratypes. The posterior sclerite of the saccus ( Fig. 12 ) is comparatively smaller than in B. japonicus or B. nepalensis ; the specimen from Uttar Pradesh differs from the holotype in a smaller number of teeth on the sclerite surface ( Fig. 13 ).

Host plants. Unknown.

Etymology. The specific epithet (masculine) refers to the three colors observed in B. tricolor : black and reddish-brown of the integument, and greyish of the dorsal vestiture.

Distribution. India, Laos, Thailand.

Figures

Figs 8–13. Bruchidius tricolor sp. nov.: 8 – male antenna; 9 – median lobe; 10 – tegmen; 11 – ovipositor (sb – sclerite in bursa copulatrix; sp – spermathecal body); 12 – detail of sclerite in saccus, holotype (Laos); 13 – detail of sclerite in saccus, specimen from Uttar Pradesh (India).

Figs 21–23. Habitus of male adults, dorsal view: 21 – Bruchidius nepalensis sp. nov.; 22 – Bruchidius tricolor sp. nov.; 23 – Bruchidius planicornis sp. nov.