Cucujus costatus Zhao & Zhang, 2019

Zhao, Ming-Zhi & Zhang, Jin-Kun, 2019, Contribution to the knowledge of the genus Cucujus Fabricius (Coleoptera, Cucujidae) from China, Zootaxa 4544 (1), pp. 144-150 : 145-146

Cucujus costatus Zhao & Zhang , new species

( Figs 1 A–C, 3A–D)

Type material. CHINA: Guangdong Province: Ƌ (Holotype, SCAU), Ruyuan County, Nanling Natural Reserve , on way from Xiaohuangshan to Shikeng, 2018-IV-4, J.- K. Zhang leg.

Holotype description. Male ( Fig. 1A ). Body length measured from apex of clypeus to apex of elytra: 17.7 mm. Color: body red, with apical teeth of mandibles, antennae, legs and abdomen black, tarsomeres dark brown at basal segment and gradually lightening towards distal segment, setae all yellowish-brown. Head ( Fig. 1 B–C): length from anterior clypeal margin to the occipital constriction: 2.6 mm, greatest width: 3.9 mm; triangular, distinctly wider than pronotum; dorsal surface with dense and large punctures, somewhat converging near frontoclypeal area, rather close and rounded on vertex, reduced on temples, front margins of clypeus and areas above antennal insertions smooth, occipital furrow dull, eyes strongly projecting and highly convex; moderately covered with short setae, clypeus with several pairs of long setae; ventral surface smooth, with quite sparse and minute punctures, genae and mentum bearing scattered, moderate-sized punctures; genae with short setae which are converging on the front and genal horns, mentum moderately setose, each side with several long setae; temples well swollen; the maximum head width 2.3 times neck width; genal horns narrow, sickle-shaped. Mandibles ( Fig. 1 B–C): dorsal and ventral surface smooth, punctures scattered and small laterad, punctures somewhat prominent near teeth; with short setae laterad and long setae along bases of apical teeth. Antennae: antennal length: 7.7 mm; punctures scattered and small; with moderate and short setae; antennomere 3 longest. Pronotum ( Fig. 1B ): length along the midline: 2.6 mm, maximum width: 3.9 mm; prolonged at the level of neck as a collar, each lateral margin with eight tubercles; with broad median cruciate depression; punctures dense and large, closer and prominent on depressions, rather reduced on margins, area around posterior angles abruptly dull with several minute punctures; with mainly moderate or short setae, with long setae along lateral margins. Prosternum ( Fig. 1C ): prosternal process elongate, expanded laterally at apex; basal portions with large and dense punctures, punctures on remainder of prosternum sparser and reduced; surface with short setae, anterior and posterior margins with moderate length pubescence. Scutellar shield: obtuse-pentagonal, slightly wider than long; with irregular, close and small punctures. Elytra ( Fig. 1A ): length from base at the level of anterior margin to apex along the suture: 11.1 mm, maximum width of both elytra together: 3.9 mm; elongate, together about 2.9 times as long as wide; each elytron with three abruptly elevated carinae; the first carina emerging near base of scutellar shield, approaching suture and becoming obsolete at anterior fifth; the second and third carinae extending from the base nearly to the apex; epipleural fold complete and prominent; sutural stria convex; with scattered and moderate size punctures, carinae and suture bordered with lines of punctures; each puncture with a short, recumbent seta, with short setae along margins, setae longer near apex of elytron. Legs: with scattered and small punctures, somewhat larger on femora; with moderate and short setae, converging near apices of tibiae. Abdomen: with confused and small punctures, smooth near sutures; abdominal sterna bearing moderate setae, posterior margin of fifth sternum with long setae. Pygidium: with small and regular punctures; with short setae, setae prolonged near apex. Male genitalia ( Fig. 3 A– D): length of tegmen: 3.2 mm, maximum width of tegmen: 0.6 mm; length of median lobe with median strut: 3.5 mm, maximum width of median lobe with median strut: 0.4 mm; slender, with parameres ventrad on median lobe; median strut about 1.9 times as long as median lobe; median lobe ( Fig. 3B ) tubular, about 3.1 times as long as wide, apex rounded, apical process protruding, dorsal margin deeply emarginate; median strut ( Fig. 3A ) widest at the base, apex broadly rounded; parameres ( Fig. 3D ) bearing tiny setae, with several long setae on apices.

Diagnosis. This species is distinguished from other Cucujus species by the distinctly elevated carinae on elytra, and the distinctly projected and convex eyes.

Distribution. China (Guangdong Province).

Etymology. The name refers to the peculiar character of the elevated carinae on the elytra.

Figures

FIGURE 1. Cucujus costatus new species, male holotype. A. Habitus in dorsal view; B–C. Head and prothorax in dorsal (B) and ventral (C) views. Scale bars: 5 mm in A; 2 mm in B–C.

FIGURE 3. Male genitalia of Cucujus spp. (A–D. Cucujus costatus new species, male holotype; E–H. Cucujus kempi) A, E. Median lobe and median strut in dorsal view; B, F. Median lobe in dorsal view; C, G. Tegmen in dorsal view; D, F. Parameres in dorsal view. Scale bars: 1 mm in A, C, E, G; 0.2 mm in B, D, F, H.