Madrasostes species

Ballerio, Alberto & Maruyama, Munetoshi, 2025, Review of Madrasostes Paulian, 1975 (Coleoptera: Hybosoridae: Ceratocanthinae) from Vietnam, with remarks on its generic limits, Zootaxa 5661 (3), pp. 420-430 : 429

Key to the Vietnamese Madrasostes species

1 Antennae with nine antennomeres. Mesotibiae always ending with a single apical spur (in males the inner apex of mesotibiae is bent inwards at a right angle but it is not a spur)................................... Pterorthochaetes Gestro, 1898 .

- Antennae with ten antennomeres. Male mesotibiae ending with two apical spurs or a single apical spur (in such a case in males the inner apex of mesotibiae is bent inwards at a right angle but it is not a spur).................................... 2

2 Labrum distinctly truncate, small species, dorsum without carinae and/or tubercles.......... Cyphopisthes Gestro, 1898 (*)

- Labrum not truncate, size variable, sometimes with dorsal carinae and/or tubercles......... Madrasostes Paulian, 1975 …3

3 Elytra without carinae (at most a hint of smooth weak carinae on apical third), pronotum without tubercles and/or carinae.. 4

- Elytra with three dorsal longitudinal sharp carinae plus two incomplete lateral ones, pronotum with tubercles and carinae... 5

4 Dorsum with sparse impressed horseshoe-shaped punctation.Color metallic green with golden, red and copper sheen. Mesotibiae ending with two apical spurs (the inner one of males bent inwards at a right angle). Volant.... M. tonkinense ( Paulian, 1945)

- Dorsum with shallower denser horseshoe-shaped punctures mixed to ocellate punctures. Dark color. Mesotibiae ending with a single apical spur (males having the apex of the inner margin of mesotibiae bent inwards at a right angle: false apical spur). Flightless........................................................................ M. deharvengi Gao, 2009 .

5 Pronotal punctation made of dense fine simple punctures................................ M. bartolozzii Ballerio, 2013

- Pronotal punctation made of large coarse irregular ocellate punctures............................. M. nomurai sp. nov.