Caenis hilaris

Caenis hilaris · Order: Ephemeroptera · Family: Caenidae

No source yet on danger. We have no source yet on whether it bites, stings or damages anything.
Caenis hilaris
Photo: Joseph Aubert, CC BY

Caenis hilaris is a small mayfly with square-shaped gills. It belongs to the family Caenidae. The species occurs in North America.

Source: Wikipedia

Size

Caenis hilaris is a small mayfly with square-shaped gills.

Source: Wikipedia

Where it comes from

Caenis hilaris is found in North America.

Source: Wikipedia

Where it is found in the US

Recorded in 14 of 51 states and DC. Most records: Illinois, Iowa, Indiana, Ohio, Florida, West Virginia, Michigan, Kansas.

Darker = more records. Counts are museum and citizen-science records, not population size.

Source: GBIF

Status: native in North America; native in Canada. Source: iNaturalist

Months it is reported in the US

JFMAMJJASOND

Source: GBIF

Same family (Caenidae)

Caenis latipennisCaenis latipennisCaenis amicaCaenis amica

Sources

  • Wikipedia: https://en.wikipedia.org/wiki/Caenis_hilaris

Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia

Text written 2026-10-27 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-27.

How this page works

This is one bug's fact sheet. The colored box at the top says whether it is dangerous. Sections below cover how to recognize it, whether it is a pest, and how to deal with it. The US map shows which states have records; tap a state to see other bugs there.

Every fact on Bug FAQ comes from a named source (university extension sites, government agencies, GBIF, iNaturalist, Wikipedia). The source is linked next to each section. If we have no source for something, we leave it out.