Metadorodocia Machatschke, 1957

Akhmetova, Lilia & Montreuil, Olivier, 2010, Revision of Metadorodocia Machatschke, 1957, a genus endemic to Madagascar (Coleoptera: Scarabaeidae: Rutelinae: Adoretini), Zootaxa 2401, pp. 61-68 : 62

Metadorodocia Machatschke, 1957

Metadorodocia – Machatschke 1957: 322.

Type species. Adoretus vittatus Waterhouse, 1878 , by monotypy.

Diagnosis. Overall size large (16–20 mm), black to brown with yellow elytral pattern.

Head flat, without any relief. Clypeus evenly rounded, its margin weakly elevated. Clypeofrontal suture thin but clearly visible, more or less sinuate in the middle. Eyes large, separated in the middle by a short canthus.

Pronotum transverse, bordered all around by a large margin. Border basomedially with very short setae. Lateral sides evenly rounded. Basal margin slightly sinuate in front of the scutellum . Front margin deeply concave, slightly sinuate in the middle. Prosternum with a tooth-shaped prominent process in the middle of its posterior margin.

Elytra with a longitudinal carina on the side, not reaching apex of elytra. Elytral striae feebly visible, marked by a row of punctures. Odd interstriae much narrower than even interstriae, weakly elevated and not punctate. Even interstriae sparsely and irregularly punctate.

Legs with shape typical to Adoretini species, with setae differing in length and thickness. The most thick and robust setae located on the mesotibiae and metatibiae. Protibiae with 3 teeth near apex of outer margin, the basal tooth weakly produced. Large claw of mesotarsi forcipate. Small claws of protarsi and mesotarsi longer than 1/2 large claws, small claws of metatarsi shorter than 1/2 large claws.

Aedeagus with parameres asymmetrical, largely opened on their dorsal side, the left paramere with a basolateral lobe. Endophallus with one long, thick sclerite attached basally and numerous small spinules medially ( Fig. 12 ).

Female genitalia ( Fig. 15 ) with membranes connecting genitalia to digestive duct, to 8th tergite and to last tergite strongly convoluted, covered with tiny, dense, and regularly distributed flat sclerotized plates that form a net. Genital plates large, square-shaped, and straight at apex.

Sexual dimorphism. Female similar to the male, except for the longer, more rounded and completely rugose apical sternite of abdomen ( Figs. 13, 14 ), and by stronger protibiae.

Distribution. This genus is endemic to Madagascar.

Natural history. The natural history of these beetles is unknown. They are probably active at night as most of the Adoretini are. One of us (OM) has observed a specimen of M. vittata attracted to light. Labels of some other specimens in collections also indicated that they were attracted to light.

Figures

FIGURE 15. Metadorodocia frolovi. Female genitalia, dorsal view (not to scale). sp — spermatheca; gs — gland of spermatheca; ov — oviduct; bc — bursa copulatrix; dd — digestive duct.

FIGURES 11 – 14. Metadorodocia. M. vittata (12), M. frolovi (13, 14). 11 — distribution map of M. frolovi and M. vittata; 12 — endophallus; 13, 14 — apical visible sternite of abdomen.