Chasmogenus Sharp, 1882

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: 146-147

publication ID

http://dx.doi.org/10.3897/zookeys.768.24423

publication LSID

lsid:zoobank.org:pub:399BCC3E-9D6F-4231-870E-05C79B9FD4B0

persistent identifier

http://treatment.plazi.org/id/1485CF5C-8A53-E50F-3345-3F8A8389FF9C

treatment provided by

ZooKeys by Pensoft

scientific name

Chasmogenus Sharp, 1882
status

 

Chasmogenus Sharp, 1882 

Chasmogenus  Sharp, 1882: 72.

Dieroxenus  Spangler, 1979: 753. Syn. n.

Discussion.

In comparing the new taxa described here to existing genera, we observed striking similarities between the monotypic Andean genus Dieroxenus  Spangler and the widespread genus Chasmogenus  Sharp. Dieroxenus  shares most diagnostic characters of New World Chasmogenus  , including general body size, the presence of sutural striae (extremely rare in Acidocerinae  ), antennae with eight antennomeres, a longitudinal carina on the mesoventrite, and a “simple” tri-lobed aedeagus ( Hebauer 1992). It does differ from Chasmogenus  in a few respects: Dieroxenus  has a slightly more robust body form, slightly shorter maxillary palps, and its elytral systematic punctures are enlarged and easily distinguished from the ground punctation. However, most if not all of these features could be attributed to the unusual seep-inhabiting nature of this species, while other Chasmogenus  are known from streams and marshes. Additionally and perhaps most convincing morphologically, is that the aedeagal form of Dieroxenus  (Fig. 21E) matches that of some Neotropical Chasmogenus  (e.g., see Figs 1-4 in Short 2005).

When Dieroxenus  was described nearly 40 years ago, the systematics and classification of the Hydrophilidae  was radically different. Chasmogenus  was then considered part of Helochares  , and most genera that are now in the Acidocerinae  were assigned to different tribes than they are today. Consequently, Spangler (1979) did not consider what we now call Chasmogenus  when making his comparisons, and instead focused on its similarities and differences from Enochrus  , which we now know is not very closely related ( Short and Fikáček 2013).

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Coleoptera

Family

Hydrophilidae

Loc

Chasmogenus Sharp, 1882

Giron, Jennifer C. & Short, Andrew Edward Z. 2018

2018
Loc

Dieroxenus

Spangler 1979

1979