Aulonothroscus laticollis

Aulonothroscus laticollis (Rybiński, 1897)

Throscus laticollis Rybiński, 1897: 56.

Throscus major Barovskij, 1933: 192.

Diagnosis. Frons without frontal keel; frontoclypeus almost straight at apical margin; pronotum about 1.5 times as wide as long; length from anterior margin of pronotum to elytral apex about 2.5 times as long as maximum width; prosternal process with marginal carinae laterally, reaching half of prosternum; mesotarsomere 3 with long spine-like process in male; aedeagus about 2.9 times as long as wide; phallobase deeply emarginate at middle on basal third, about 1.9 times as long as wide; parameres widest at middle, slightly arcuate laterally, abruptly narrowing apically, apex round and extending inward, shortly setose on lateral surface; median lobe stout, about half as long as parameres.

Redescription (Fig. 1). Male. Body (Figs. 1A–C) 3.1 mm long and 2.1 mm wide; elongate-oval and convex; widest at basal fourth of pronotum, length from anterior margin of pronotum to elytral apex about 2.5 times as long as maximum width; surface coloured black-brown, densely covered with recumbent setae. Head (Fig. 1D) deeply inserted into prothorax, densely punctate; frons without frontal keel; anterior margin of frontoclypeus almost straight; compound eyes complete, without emargination; antennae 11-segmented, with 3-segmented loose antennal club; scape elongate-oval; pedicel asymmetrical, almost as long as wide; flagellomeres 3–8 subequal, closely attached to each other; flagellomeres 9 and 10 about 1.7 and 1.6 times wider than long, respectively; apical flagellomere asymmetrical, about 2.1 times longer than wide. Pronotum subtrapezoidal, subparallel-sided at basal fourth, then abruptly narrowed anterad; about 1.5 times as wide as long; anterior margin weakly arcuate; disc evenly covered with deep punctures, similar sized and sparser than those of head, rather coarser and denser basally and laterally; intermingled with sparse microscopic punctures between large punctures. Scutellar shield subtriangular, gradually narrowed posterad; as long as wide; covered with fine punctures and setae. Elytra subparallel-sided, weakly narrowed posterad from basal half; about 1.9 times as long as wide; elytral stria complete; interstriae subflattened, mostly with two rows of punctures at anterior half, and single row posteriorly. Prosternum subparallel-sided, gradually narrowed anterad; anterior margin weakly trilobate; prosternal process with marginal carinae laterally, reaching half of prosternum; hypomeron with transverse impression at apical a third, forming deep cavity anteriorly and posteriorly; anterior cavity connected with anteriorly open notosternal groove to receive antennae; posterior cavity housing prothoracic leg. Metasternum evenly covered with deep punctures, smaller and sparser than those of prosternum, sparsely scattered with microscopic punctures between deep punctures; oblique mesotarsal groove (Figs. 1B–C) deep, well-developed, extending from underneath mesocoxa to posterior angle of metasternum. Abdomen with five abdominal ventrites, strongly connated; evenly punctate as metasternum, becoming larger and coarser marginally; densely setose; ventrite 5 narrowly rounded at apex, laterally smooth. Aedeagus (Figs. 1G–L) trilobed, about 2.9 times as long as wide; phallobase deeply emarginate at middle on basal third, about 1.9 times as long as wide; parameres widest at middle, slightly arcuate laterally, abruptly narrowing apically, apex round and extending inward, shortly setose on lateral surface; median lobe stout, about half as long as parameres. Legs moderately long, slender; mesotarsi (Figs. 1E–F) short, about 0.3 times as long as midtibia; tarsomere 1 as long as 2–3 combined; tarsomere 3 distinctly modified, with hook-like process on ventral surface. Female not available during the course of this study.

Material examined. (1) 1 male. Republic of Korea, Jeongbae-ri, Seojong-myeon, Yangpyeong-gun, Gyeonggi-do, 05–18.VI.2022, Seung et al. leg., by flight intercept trap (SNU).

Distribution. Korea (New record), Europe (Belarus, Croatia, Finland, France, Norway, Poland), Japan, Russia.

Remarks. This species has a wide range in the Palaearctic region, from Europe to East Asia. Burakowski, (2000) as well as Nomura & Hirano (2014) provided other information for A. laticollis, including female data and illustrations.