Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Clickable Guide
Moths Butterflies Flies Caterpillars Flies Dragonflies Flies Mantids Cockroaches Bees and Wasps Walkingsticks Earwigs Ants Termites Hoppers and Kin Hoppers and Kin Beetles True Bugs Fleas Grasshoppers and Kin Ticks Spiders Scorpions Centipedes Millipedes

Upcoming Events

Photos of insects and people from the 2022 BugGuide gathering in New Mexico, July 20-24

National Moth Week was July 23-31, 2022! See moth submissions.

Photos of insects and people from the Spring 2021 gathering in Louisiana, April 28-May 2

Photos of insects and people from the 2019 gathering in Louisiana, July 25-27

Photos of insects and people from the 2018 gathering in Virginia, July 27-29

Photos of insects and people from the 2015 gathering in Wisconsin, July 10-12

Previous events


Genus Thermonectus

Aquatic beetle - Thermonectus basillaris Dytiscidae? maybe Eretes sp. - Thermonectus sibleyi Dytiscidae? maybe Eretes sp. - Thermonectus sibleyi Sunburst Diving Beetle - Thermonectus marmoratus Thermonectus marmoratus T. n. nigrofasciatus - Thermonectus nigrofasciatus Water beetle - Thermonectus basillaris - male Thermonectus marmoratus
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Coleoptera (Beetles)
Suborder Adephaga (Ground and Water Beetles)
Family Dytiscidae (Predaceous Diving Beetles)
Subfamily Dytiscinae
Tribe Aciliini
Genus Thermonectus
Explanation of Names
Thermonectus Dejean 1833
6 spp. in our area, 20 total(1)(2)
7.5-14 mm(3)
elytron densely punctate but punctures fine and inconspiciuous, AND mesofemur with hind margin setae longer than width of femur(4)
New World, mainly warm temperate to tropical; T. basilaris strays as far north as so. ON(3)
Mostly in ponds, both permanent and vernal; 2 spp. in desert streams; come to lights(3)
Life Cycle
adults reported to overwinter on land, breeding in late spring to early summer, larvae develop quickly over the summer, especially in desert regions(3). Newly emerged adults disperse to overwintering sites in late summer and into the fall.
Works Cited
1.A World Catalogue of the Family Dytiscidae, or the Diving Beetles (Coleoptera, Adephaga)
Nilsson and Hajek. 2019. Distributed by authors.
2.The Water Beetles of Florida
Epler J.H. 2010. Florida Department of Environmental Protection. Tallahassee. 414 pp.
3.Predaceous Diving Beetles (Coleoptera: Dytiscidae) of the Nearctic Region, with emphasis on the fauna of Canada and Alaska
D.J. Larson, Y. Alarie, and R.E. Roughley. 2001. NRC 43253.
4.American Beetles, Volume I: Archostemata, Myxophaga, Adephaga, Polyphaga: Staphyliniformia
Arnett, R.H., Jr., and M. C. Thomas. (eds.). 2000. CRC Press LLC, Boca Raton, FL.