Bug FAQCrambidia impura
Crambidia impura · Order: Lepidoptera · Family: Erebidae
Adult Crambidia impura moths are light grey in color. They are found in the southern Rocky Mountain states as well as the Yukon, northern British Columbia and Alberta. Adults fly from August through September and the larvae probably feed on lichens.
Source: Wikipedia
How to recognize it
Adults are light grey.
Source: Wikipedia
What it eats
The larvae probably feed on lichens.
Source: Wikipedia
When you see it
Adults are active in late summer, specifically August and September.
Source: Wikipedia
Where it is found in the US
Recorded in 6 of 51 states and DC. Most records: Colorado, Arizona, Wyoming, New Mexico, Utah, Texas.
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
Questions people ask
When are adult Crambidia impura moths active?
Adults fly from August through September.
Source: Wikipedia
Same family (Erebidae)
Spongy MothLymantria disparDamages trees, gardens or crops
Fall Webworm MothHyphantria cuneaDamages trees, gardens or crops
Brown-tail MothEuproctis chrysorrhoeaCan irritate skin
Isabella Tiger MothPyrrharctia isabella
Virginian Tiger MothSpilosoma virginicaCan irritate skin
Salt Marsh MothEstigmene acreaDamages trees, gardens or cropsSources
- Wikipedia: https://en.wikipedia.org/wiki/Crambidia_impura
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-26 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-26.