Bomansius Lacroix, 1978, 1979

Kakinuma, Shunsuke, 2019, A new species of Bomansius Lacroix (Coleoptera: Lucanidae) from Vanuatu, with redescriptions of its genus and its only congener, Bomansius gabrieli Lacroix, 1978, Insecta Mundi 728 (728), pp. 1-12 : 2-3

Genus Bomansius Lacroix, 1978

Bomansius Lacroix 1978: 288 .

Type species. Bomansius gabrieli Lacroix 1978: 289 , by original designation.

Genus Redescription

Length: (including mandibles) 11.5–17.5 mm, (excluding mandibles) 10.4–14.2 mm. Width: 5.4–8.6 mm. Color: Body black, sometimes brownish. Shape: Body somewhat oval, very convex and thick overall. Head: Form large, wide especially in larger male. Labrum fused to clypeus, short and concave in males, trapezoidal or weakly concave in females, with long, yellow, dense hairs except at middle. Eyes small, located behind middle of head, totally divided (anterior and posterior canthi adjoined; Fig. 11–12 , 28–31 ) or almost but not totally divided ( Fig. 13–14 , 26–27 ) by a long anterior canthus and a very short posterior canthus. Mandibles falciform, slender, moderately short, almost as long as or slightly shorter than head; inner margin at the base covered with very dense long hairs. Male mandibles with two inner teeth (one dorsomedial and one basal ventromedial); apex simple. Female mandibles acute, with one simple inner tooth. Antennae geniculate, 10–segmented; antennal club (articles 8–10) entirely tomentose, shorter than funicle; scape slightly shorter than club plus funicle in males, much shorter in females. Mentum much wider than long, weakly bilobed. Labial palp with terminal article weakly dilated. Lacinia of maxilla without hook. Pronotum: Form convex, wider and longer than head; lateral edges with punctures and sparse setae. Lateral and basal margins raised like gut- ter. Scutellum: Form short, semicircular. Elytra: Form very short, somewhat circular, strongly convex; suture fused; surface covered with large punctures, not distinctly grooved longitudinally; striae absent or vague; edge with sparse setae on lateral sides. Wings atrophied, very small ( Fig. 15 ). Legs: Protibia gradually widening toward apex; apical tooth large, bidentate. Mesotibia and metatibia with rows of long, yellow setae on surface. Setae on ventral surface of joints of tarsomeres long. Abdomen: Ventrites setose; setae denser and longer in males, sparser and shorter in females. Male genitalia ( Fig. 16 , 32 ): 9th abdominal segment with proximal half of sternite (ventral plate) circularly sclerotized. Aedeagus with moderately broad, permanently everted internal sac; internal sac weakly widened, sclerotized, clothed with microsetae from apex to less than half of the length. Base of internal sac with a dorsal crossbar, without a pair of projections on dorsal crossbar nor lateral bridge; lateral lobes at the base of internal sac long, narrowly sclerotized, distal part somewhat sagittate; paired struts present.

Diagnosis. Bomansius is separated from other genera of Aegini by the following characters: very short and convex form; mandibles slender; elytra fused along suture and not distinctly grooved longitudinally; wings atrophied; apical tooth of protibia large and bidentate; male aedeagus with broader and shorter internal sac, lateral lobes at the base of internal sac sclerotized in sagittate shape. Bomansius is easily distinguished from many of the other flightless genera of Lucaninae present in Australasia realm ( Lissotes , Hoplogonus , Geodorcus Holloway , Paralissotes Holloway ) by the totally or almost totally divided eye, from Lissapterus by having an entirely tomentose antennal club, and from Microlucanus Bomans and Bartolozzi by the mostly glabrous dorsum and elytral edge without crenulations.

Figures

Figures 8–16. Bomansius cheesmanae new species, paratypes. 8–10) Males, dorsal habitus. 11–14) Eyes. 11–12) Male, eyes totally divided by canthi. 11) Dorsal view. 12) Lateral view. 13–14) Female, eyes not totally divided by canthi. 13) Dorsal view. 14) Lateral view. 15) Atrophied wing of male. 16) Male aedeagus with sternite of 9th abdominal segment, ventral view.

Figures 23–32. Bomansius gabrieli. 23–24) Males, dorsal habitus. 25) Holotype male (after Lacroix 1978). 26–31) Eyes. 26–27) Male, eyes not totally divided by canthi. 26) Dorsal view. 27) Lateral view. 28–29) Male, eyes totally divided by canthi. 28) Dorsal view. 29) Lateral view. 30–31. Female, eyes totally divided by canthi. 30) Dorsal view. 31) Lateral view. 32) Male aedeagus with sternite of 9th abdominal segment, ventral view.