Madagastrini, Perkins, 1997

Perkins, Philip D., 2017, Hydraenidae of Madagascar (Insecta: Coleoptera), Zootaxa 4342 (1), pp. 1-264 : 170

Key to the genera of Madagastrini

1. Elytral ridges carinate, strong, continuous; third carina (counting sutural carina as first), arcuate posteriorly and attaining elytral apices at or very near sutural angle; intercostal areas with two or three rows of punctures.......................... 2

-. Elytral ridges low and continuous or, if carinate, sometimes with interrupted sections; ridges or carinae not attaining elytral margin; areas between ridges with three to five rows of punctures or granules...................................... 4

2. Head with clypeus laterally widened, labrum and maxillary palpi short and held beneath overhanging clypeus; hydrofuge pubescence on abdominal ventrites reduced, less than first four ventrites plus anterior margin of fifth................... 3

-. Clypeus not widened, maxillary palpi larger, exposed; hydrofuge pubescence on first four abdominal ventrites and anterior margin of fifth; India ( Fig. 174)............................................................... Gondraena Jäch

3. Pronotum with tuberculate carinae; posterior angles of pronotum deeply excavate; hydrofuge pubescence on first two abdominal ventrites; India........................................................................ Davidraena Jäch

-. Pronotum non-carinate, with circular, flat, dense granules; posterior angles of pronotum not excavate; abdominal ventrites lacking hydrofuge pubescence ( Figs. 162, 163, 166 , 167 , 170, 171); Madagascar.............. Menomadraena new genus

4. Prosternum with coxal cavities closed behind; mesoventrite intercoxal process with small tubercle ( Fig. 191); each elytron with four strong carinate ridges, the first of which is interrupted in one place; hydrofuge pubescence on first three ventrites and anterior margin of fourth; Madagascar................................................ Trinomadraena new genus

- Prosternum with coxal cavities open behind; mesoventrite intercoxal process without tubercle; elytral ridges variable, low and continuous or if carinate with interrupted areas; hydrofuge pubescence variable, on first two ventrites and anterior margin of third or on first four and anterior margin of fifth; Madagascar.................................... Madagaster Perkins

Figures

FIGURE 166. Menomadraena sembella, holotype, habitus dorsal, lateral, and ventral.

FIGURE 167. Menomadraena andringitra, holotype, habitus dorsal, lateral, and ventral.