Bug FAQEthmia semitenebrella
Ethmia semitenebrella · Order: Lepidoptera · Family: Ethmiidae
The forewings are 10.1 to 14.3 mm long and show a dark gray costal half and a whitish-gray dorsal half with longitudinal streaks formed by whitish overscaling between the veins.
Source: Wikipedia
How to recognize it
Whitish overscaling between the veins creates longitudinal streaks, especially beyond the middle of the wing.
Source: Wikipedia
What it eats
Larvae feed on the plant Cercocarpus ledifolius and probably other Cercocarpus species.
Source: Wikipedia
When you see it
Adults are active from April through August.
Source: Wikipedia
Where it comes from
Its native range includes the western United States and northern Mexico.
Source: Wikipedia
Where it is found in the US
Recorded in 11 of 51 states and DC. Most records: California, Arizona, New Mexico, Montana, Wyoming, Idaho, Nevada, Oregon.
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
Questions people ask
When are adult Ethmia semitenebrella moths active?
Adults fly from April to August and there are two generations each year.
Source: Wikipedia
What do the larvae of Ethmia semitenebrella eat?
The larvae feed on Cercocarpus ledifolius and likely other Cercocarpus species.
Source: Wikipedia
Same family (Ethmiidae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Ethmia_semitenebrella
Look it up elsewhere: GBIF · iNaturalist · BugGuide · Wikipedia
Text written 2026-10-25 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-25.