Brachytrycherus conaensis, Chang, Ling-Xiao, Bi, Wen-Xuan & Ren, Guo-Dong, 2016

Chang, Ling-Xiao, Bi, Wen-Xuan & Ren, Guo-Dong, 2016, Two new species of Brachytrycherus Arrow, 1920 from China (Coleoptera, Endomychidae), ZooKeys 595, pp. 137-146 : 139

Taxon classification Animalia Coleoptera Endomychidae

Brachytrycherus conaensis sp. n. Figs 1-2, 5

Type material.

Holotype, male, Xizang, Cona, Lexiang, 2500-2600 m, 20-30.VI.2013, Wen-Xuan Bi leg. (MHBU); Paratypes, 1 female, same data as holotype. 2 females, Xizang, Medog, Beibeng, Gelincun, 1700 m, 3.VIII.2014, Wen-Xuan Bi leg. (CBWX); 3 males, 7 females, Xizang, Cuona, Lexiang, 2500 m, 6.VIII.2010, Wen-Xuan Bi leg. (CBWX); 5 males, 6 females, ditto except 15.VII.2011 (CBWX); 26 males, 11 females, ditto except 29-30.VI.2013 (CBWX); 1 male, 1 female, ditto except (MZPW); 18 males, 1 female, ditto except 2500-2600 m, 20-30.VI.2013 (CBWX); 1 female, ditto except 2700 m, 18.VI.2013 (CBWX).

Etymology.

The specific name is derived from the type locality.

Diagnosis.

Brachytrycherus conaensis is similar to Brachytrycherus madurensis in appearance, but can be differentiated by each elytron with three maculae, anterior two maculae nearly rhomboid in shape, sometimes connected to each other, and the anterior and posterior elytral maculae without dentition.

Description.

Length 8.2-8.3 mm. Body oval, about 1.8-1.9 times as long as wide; rather convex; shiny. Colour black with three red maculae on elytra.

Head. Antenna 11-segmented, long and rather slender, nearly 1/2 body length, with antennomeres 1-8 distinctly longer than wide; scape approximately 4.5 times as long as pedicel; antennomere 3 slightly shorter than 4 and 5 combined; antennomeres 4 nearly as long as 5, antennomeres 5-8 gradually shorter; club composed of 3 antennomeres, moderately broad, flat, loose. Maxilla with terminal palpomere elongated, almost 2.0 times as long as palpomere 3, tapering anteriorly, truncate apically.

Thorax. Pronotum 2.0-2.3 mm long, 3.2-3.3 mm wide; widest near 1/2 of pronotal length; coarsely and densely punctate; lateral margins rather narrowly bordered, sides nearly parallel; front angles produced anteriorly, rather acute; disc weakly convex, two small round raised area laterally; transverse wrinkle laterally; median furrow absent; lateral sulci linear, deep, extending to basal 1/3 length of pronotum; basal sulcus nearly straight, deep. Prosternal process rather narrowly separates procoxae; not extending beyond coxae; sides in male weakly curved outwardly, rounded apically; in female sides nearly straight, weakly truncate apically. Mesoventral process transverse, lateral margins widening apically and overlapping part of mesocoxae; posterior margin nearly straight. Elytra 5.9-6.1 mm long, 4.5-4.7 mm wide; 2.7-3.0 times as long as pronotum and 1.4 times as wide as pronotum, sides curved, widest near 1/2 length of elytron; densely and coarsely punctate; humeri rather prominent. Each elytron with three irregular red maculae. Anterior 2 elytral elytral maculae nearly rhombus, located near apical 1/4, medial macula larger than lateral one, sometimes narrowly connected. Posterior macula transverse, anterior margin shallowly emarginate or nearly straight, posterior margin U-shaped, widely emarginate.. All tibiae with sexual characters; protibiae in male with concavity on inner edge of apical 1/4, in female without concavity; mesotibiae abruptly curved from near apical 1/3 to apex, in female gently curved; metatibiae in male abruptly widened from near 1/3 length to apex, in female gently widened.

Abdomen with five ventrites in both sexes. Ventrite 5 with lateral margins gently converging posteriorly, three pairs of longitudinal short wrinkles laterally; posterior margin weakly curved medially in male; in female ventrite 5 lateral margins abruptly converging posteriorly, without longitudinal wrinkles; posterior margin truncate, nearly straight medially. Aedeagus (Fig. 5) rather long, heavily sclerotized, straight. Median lobe branched apically; branch long and rather straight, abruptly raised near basal 1/3 length, gently converging apically, flat, acute and weakly reflexed apically. Tegmen basal, comparatively large, ring-shaped.

Biology and ecology.

Almost all individuals were found active on fence, woodpile or timber piles within the village and its surrounding area at night (Figs 9-11). Some larvae and adults were found (sometimes at the same time) feeding on the surface of the perithecia or spores of Daldinia concentrica ( Xylariaceae ) (Fig. 10), seeming to prefer the asexual phase; however, individuals were also found on mature ascocarps.

Based on the study of the natural history of the handsome fungus beetles ( Shockley et al. 2009b), this report is possibly the first record of the handsome fungus beetles feeding on ascomycetes. In addition, some individuals were found active on the wood without fungus, and may be feeding on lichen growing on the wood (Fig. 11). This species association may not be host-specific.