Bug FAQSpeckled Dun
Callibaetis pictus · Order: Ephemeroptera · Family: Baetidae
Also called: Speckled Spinner
The speckled dun is a small minnow mayfly. It has a pale W-shaped marking on the back of its sixth abdominal segment, with similar marks often on the fifth and ninth segments. It lives in Central America and across Mexico, the northern, and southwestern United States.
Source: Wikipedia
How to recognize it
A pale W-shaped dorsal mark on tergite 6 distinguishes it, and similar marks are usually on tergites 5 and 9.
Source: Wikipedia
Size
It is a small minnow mayfly.
Source: Wikipedia
Where it comes from
Found in Central America and North America, including all of Mexico and the northern and southwestern United States.
Source: Wikipedia
Where it is found in the US
Recorded in 13 of 51 states and DC. Most records: California, Arizona, New Mexico, Texas, Colorado, Oregon, Michigan, Nevada.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in North America; native in United States. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Same family (Baetidae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Callibaetis_pictus
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.