Bug FAQThermonectus basillaris
Thermonectus basillaris · Order: Coleoptera · Family: Dytiscidae
Adult Thermonectus basillaris are about 8 to 11 mm long and 5 to 6 mm wide. They live in temporary ponds, can fly readily, and are found in the eastern United States, southern Ontario, and Cuba.
Source: Wikipedia
Size
Adults measure roughly 8.1 to 10.7 mm in length and 4.7 to 5.9 mm in width.
Source: Wikipedia
Where it lives
This beetle is a pioneering species that occupies temporary ponds and is a strong flyer.
Source: Wikipedia
Where it is found in the US
Recorded in 32 of 51 states and DC. Most records: Texas, Florida, Louisiana, Alabama, Oklahoma, North Carolina, Mississippi, Illinois.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in North America; native in Canada; native in United States. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
What kind of habitat does Thermonectus basillaris prefer?
It lives in temporary ponds and can fly readily.
Source: Wikipedia
Same family (Dytiscidae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Thermonectus_basillaris
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-23 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-23.