Calodera lunata, Assing, 2003

Assing, Volker, 2003, A revision of Calodera Mannerheim. III. A new species from Russia and a key to the Palaearctic species of the genus (Coleoptera: Staphylinidae: Aleocharinae), Zootaxa 311 (1), pp. 1-7 : 2-4

Calodera lunata sp. n. ( Figs. 1–5 )

Holotype ♂: " Russland: Komi ASSR, Uchta, Aeroport, Fichtenwald , 24.VI.1971, leg. Schilow / Holotypus ♂ Calodera lunata sp. n. det. V. Assing 2002" ( DEI).

Description. Externally somewhat resembling C. desdemona Sharp, 1888 and C. zerchei Assing, 2003 , or a small specimen of C. rufescens Kraatz, 1856 ( Fig. 1 ). Measurements of holotype (in mm): head length: 0.36, head width: 0.36; length of pronotum: 0.45; width of pronotum: 0.44; length of elytra at suture from apex of scutellum to elytral hind margin: 0.39 mm; length of metatibia: 0.51; length of metatarsus: 0.32; total length: 3.2 mm. Coloration: dark brown, with the posterior margins of the abdominal segments, the abdominal apex, the tarsi, the mouthparts, and the basal antennomeres somewhat lighter.

Head shape as in C. rufescens ( Fig. 2 ); microsculpture shallow; puncturation sparse and extremely fine; eyes in dorsal view approximately as long as temples, weakly projecting from lateral outline of head; neck distinctly wider than in C. rufescens , about as wide as in C. desdemona , i. e. approximately 0.7 times as wide a maximal width of head. Antenna as in C. rufescens , but with somewhat more transverse antennomeres IV ­ X.

Pronotum as wide as long and about 1.2 times as wide as head; otherwise of similar shape and puncturation as in C. rufescens .

Elytra at suture 0.9 times as long as pronotum; puncturation somewhat granulose, denser and coarser than in C. rufescens .

Abdomen with fine, but distinct puncturation; anterior transverse impressions of tergites III ­ VI finely punctate; microsculpture present on all tergites, shallow on tergites III ­ VI and very distinct on tergite VII.

♂: sternite VIII indistinctly pointed in the middle; median lobe of aedeagus smaller than in C. rufescens , of similar size as in C. desdemona ; subapical structures of distinctive shape, especially in ventral view ( Figs. 3–5 ).

♀: unknown.

Comparative notes. In the Western Palaearctic congeners, except for C. lapponica J. Sahlberg, 1876 , the neck of the head is either longer and distinctly narrower (most species), or wider ( C. nigrita Mannerheim, 1830 ) than in C. lunata , or reduced to a fine carina ( C. protensa Mannerheim, 1830 , C. rubens Erichson, 1837 ). Similarity in the external characters and the aedeagus, especially the morphology of the posterior constriction of the head, suggests closer phylogenetic affinities of C. lunata to the Eastern Palaearctic C. desdemona and C. zerchei than to Western Palaearctic congeners. Both species are, however, distinguished from C. lunata by the characteristic shapes of the subapical structures of the aedeagus (see figures in Assing 2003). In addition, C. desdemona , which is of similar size, is separated by a less pronounced microsculpture of the abdomen and relatively longer elytra. C. zerchei is smaller (width of pronotum: 0.38 mm), has legs of lighter (reddish brown) coloration, a more slender head (width: 0.32 mm), and more finely punctate elytra ( Figs. 6–7 ).

Distribution. Calodera lunata is currently known only from the environs of Ukhta, Komi Republic, but very likely to be much more widespread.

Figures

FIGURES 1–8. Calodera lunata sp. n. (1–5), C. zerchei Assing (6–7), and Parocyusa hebeiensis (Pace) (8): 1, 7, 8 — facies; 2 — head and pronotum; 3 — median lobe of aedeagus, lateral view; 4 – median lobe of aedeagus, ventral view; 5 — apical part of median lobe of aedeagus, ventral view; 8 — forebody. Scale bars: 1, 6, 8: 1.0 mm; 2, 7: 0.5 mm; 3, 4: 0.2 mm; 5: 0.1 mm.