Cymbiodyta bifidus

Cymbiodyta bifidus is a species of hydrophilid beetle. The species was formerly the sole member of the genus Helocombus.^[1][2][3]

Cymbiodyta bifidus
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Coleoptera
Family:	Hydrophilidae
Genus:	Cymbiodyta
Species:	C. bifidus
Binomial name
Cymbiodyta bifidus (LeConte, 1855)
Synonyms
Helocombus bifidus

Cymbiodyta bifidus, Oklahoma, 7.6 mm

Description

Adult size ranges from 5.5 to 7.8 millimetres (0.22 to 0.31 in) in length. Their maxillary palpi are long and slender with the last segment shorter than the preceding segment and the pseudobasal segment concave inwardly. There is a pyramidal projection medially on the mesosternum, and the elytra have distinct striations. The middle and hind tarsi have four segments, while tarsal claws have a basal tooth in both males and females.^[4]

The antennae on larvae have basal segments that are slightly shorter of subequal to the remaining segments, with sensorium on the apex of segment 2. The labroclypeus has several smaller central teeth and two larger teeth on each side. The mandibles are symmetrical, and both have two inner teeth. Larvae also have well developed legs, and the ligula is subequal to the length of the first palpal segment.^[4]

Distribution

Cymbiodyta bifidus ranges across much of eastern North America from Labrador south to central Florida and west to the Great Plains. It has been collected from pond and lake habitats containing emergent vegetation, such as sedges, as well as in slow moving streams.^[4][5][6]

References

1. Toussaint, Emmanuel F. A.; Short, Andrew E. Z. (2019). "Historical Biogeography of Holarctic Cymbiodyta Water Scavenger Beetles in the Times of Cenozoic Land Bridge Dispersal Routes". Insect Systematics and Diversity. 3 (5). doi:10.1093/isd/ixz017.
2. "Helocombus bifidus (LeConte, 1855)". Integrated Taxonomic Information System. Retrieved July 28, 2015.
3. Short, Andrew E.Z.; Fikåček, Martin (2011). "World catalogue of the Hydrophiloidea (Coleoptera): additions and corrections II (2006-1010)" (PDF). Acta Entomologica Musei Nationalis Pragae. 51 (1): 83–122. Archived from the original (PDF) on August 13, 2015.
4. Epler, John H. (2010). "The Water Beetles of Florida" (PDF). Florida Department of Environmental Protection. {{cite journal}}: Cite journal requires |journal= (help)
5. Whiteman, Noah; Sites, Robert W. (2001). "Aquatic Poyphaga (Coleoptera) state records from the Missouri Prairie Region" (PDF). Journal of the Kansas Entomological Society. 74 (2): 101–105. Archived from the original (PDF) on March 5, 2016.
6. Fairchild, G. Winfield; Cruz, Jason; Faulds, Ann M. (2003). "Microhabitat and landscape influences on aquatic beetle assemblages in a cluster of temporary and permanent ponds" (PDF). Journal of the North American Benthological Society. 22 (2): 224–240. doi:10.2307/1467994. JSTOR 1467994. S2CID 84915378. Archived from the original (PDF) on July 28, 2015.