Calloserica lachungensis, Ahrens, 2000

Ahrens, Dirk, 2000, New species of Calloserica Brenske, 1894 from Sikkim and Nepal (Coleoptera, Melolonthidae, Sericini), Zoosystema 22 (4), pp. 815-824 : 817-818

Calloserica lachungensis n. sp.

( Fig. 2 )

TYPE MATERIAL. — Holotype:, British India Sikkim Lachen-Lachung , VIII.1933 / Muséum Paris ex. Coll. R. Oberthur ( MNHN).

ETYMOLOGY. — The species is named after locality Lachung.

A C

DESCRIPTION

Length: 9.3 mm, width: 5.3 mm, length of elytra: 7.4 mm.

Body oblong, chestnut, with opaque tomentum, elytral striae lighter, labroclypeus shiny, dorsal surface erectly hairy.

Labroclypeus shiny, transverse, sides convexly narrowed anteriorly, all borders strongly reflexed and anterior margin deeply sinuate at middle, front angles abruptly rounded; labrum broadly trapezoidal and anteriorly produced, longest extension medially; clypeal surface densely punctate, punctures slightly elevated, with fine setae. Frontoclypeal suture weakly curved; smooth area in front of eye 1.5 time as wide as long, ocular canthus long and slender, with few setae. Punctures on frons vanishing under thick opaque tomentum, only recognizable by their long erect setae. Antenna yellow, 10-segmented; club 4-segmented, a trifle longer than combined lengths of remaining segments, seventh segment one-third shorter than club. Eyes small, ratio diameter/interocular width: 0.56.

Pronotum transverse, widest at base, lateral margin subparallel from base to middle, anteriorly strongly curved, anterior angles bluntly rounded, not protudent, anterior margin straight; general shape similar to that of C. tigrina , but sides posteriorly not sinuate before obtusely rounded hind angles; disc with shallow punctation, double erect pilosity directed forward, mixed short and two times longer setae. Proepisternum weakly grooved, posterior border produces with pronotal base a sharp, distinctive angle. Scutellum oblong, triangular, densely punctate, basally with a deep transverse impression.

Elytra oblong, intervals flat, mixed coarse punctures bearing long, erect, forward directed setae with groups of fine punctures bearing short white scales; apex membranous.

Ventral surface including metacoxal plates, femora, and abdominal sternites clothed with fine, recumbent, yellow setae. Abdominal sternites without any elevation. Mesosternum between mesocoxae equal in width to slender mesofemur. Ratio of length metepisternum/ metacoxa: 1/1.2. Pygidium convex, densely and shallowly punctate, with double pilosity, long setae four times longer than the short.

Metatibia slender, ratio width/length: 1/4.2; dorsally longitudinally carinate, with two groups of spines, the proximal one situated at middle of metatibial length, basally few small setae on a longitudinal elevation; outside longitudinally grooved, dorsally coarsly wrinkled, ventral edge with four tubercles bearing a strong seta. Metatarsal segments laterally carinate, first metatarsomere almost as long as following two segments combined, one-third longer than superior metatibial spur; mesotarsal segments laterally not carinate, dorsally without longitudinal impressions. Anterior tibia short, bidentate, external border with a blunt median extension.

REMARKS

The species is externally similar to C. brendelli Ahrens, 1999 . It differs by ratio of length of first metatarsomere with the combined lengths of the second and third metatarsomeres. C. bertiae n. sp. (Sikkim) and C. lachungensis n. sp. seem closely related because of their similar features of male genitalia. They differ from each other by size of parameres and aedeagus, both can be distinguished from the genitalitary very similar C. brendelli Ahrens, 1999 by the shorter parameres ( Fig. 2 ) (Ahrens 1999: 187, figs 6-8).

Female unknown.

Figures

FIG. 2. — Calloserica lachungensis n. sp. (holotype), male genitalia; A, C, aedeagus, lateral view; B, parameres, dorsal view. Scale bar: 1 mm.