Chasmogenus cremnobates (Spangler, 1979), 2018

Giron, Jennifer C. & Short, Andrew Edward Z., 2018, Three new genera of acidocerine water scavenger beetles from tropical South America (Coleoptera, Hydrophilidae, Acidocerinae), ZooKeys 768, pp. 113-158 : 147-148

Chasmogenus cremnobates (Spangler, 1979) comb. n. Fig. 21

Dieroxenus cremnobates Spangler, 1979: 754

Type material examined.

Holotype: "ECUADOR: Napo, Baeza (72 km E), 16 May 1975, Spangler, Langley, and Cohen" (USNM). Paratypes: ECUADOR: Napo: same data as holotype (44 males; 42 females); Tungurahua: “Baños (35 km E), 29 May 1975, Langley, Cohen, and Monnig (8 males; 6 females); “Baños (18 km E), 25 Jan 1976, Spangler, et al. (15 males; 18 females); “Baños (20 km E), 28 Jan 1976, Spangler, et al. (7 males; 6 females); “Baños (39 km E), 28 Jan 1976, Spangler, et al. (2 females).

Additional material.

ECUADOR: Napo: " San Francisco de / Borja 17 Jan 1978 / 1610 m PJ Spangler/ & J. Anderson // seep on stream bank" (6 males, 6 females; USNM) .

Key to the genera of New World Acidocerinae

1	Eyes absent. Known only from a cave in Ecuador	Troglochares
-	Eyes present	2
2	Eyes completely divided into dorsal and ventral sections by a lateral projection of frons. Size small (<3 mm)	Quadriops
-	Eyes not divided into dorsal and ventral sections by frons. Size variable	3
3	Labrum concealed by clypeus, elytral margins broadly explanate. Body extremely dorsoventrally compressed	Helobata
-	Labrum not concealed by clypeus elytral margins not or at most weakly explanate. Body form variable but rarely dorsoventrally compressed	4
4	Elytra with distinctly impressed sutural striae. Only Neotropical region	Chasmogenus
-	Elytra without sutural striae. Both Neotropical and Nearctic	5
5	Prosternum with strongly elevated median carina	Crucisternum
-	Prosternum without median carina; at most tectiform medially	6
6	Metafemora entire glabrous. Size small (<3 mm)	Tobochares
-	Metafemora pubescent at least on basal half or anterior third. Size variable	7
7	Fifth ventrite entire, without apical emargination or truncation. Antennae with nine antennomeres. Maxillary palps shorter than the width of the head	Radicitus
-	Fifth ventrite with apical emargination or truncation. Antennae with eight or nine antennomeres. Maxillary palps variable in length	8
8	Elytral systematic punctures very distinct, distinctly larger than surrounding ground punctation. Antennae with nine antennomeres	Katasophistes
-	Elytral systematic punctures indistinct, usually blending with surrounding ground punctation. Antennae with eight or nine antennomeres	9
9	Antennae with nine antennomeres. Size variable, but rarely less than 4 mm. Extremely common and widespread throughout the New World	Helochares
-	Antennae with eight antennomeres. Rare and only known from the Guiana Shield region of South America. Size very small (<3 mm)	10
10	Body form circular, rounded. Size very small (1.9-2.3 mm)	Globulosis
-	Body form ovoid, parallel sided. Size exceedingly small (1.1-1.5 mm)	Nanosaphes

Figures

Figure 21. Habitus of Chasmogenus cremnobates: A dorsal view B lateral view C ventral view D head E aedeagus. Scale bar 1 mm.