Bug FAQChestnut-marked Pondweed Moth
Parapoynx badiusalis · Order: Lepidoptera · Family: Crambidae
The chestnut-marked pondweed moth has a wingspan of about 20 mm and was first described by Francis Walker in 1859. It lives around vegetated ponds, marshes and lake shores across many U.S. states and Canadian provinces, and its larvae feed on pondweed (Potamogeton) species. Adults are on the wing from May through September.
Source: Wikipedia
How to recognize it
Francis Walker first described this species in 1859.
Source: Wikipedia
Size
The moth’s wingspan is roughly 20 mm.
Source: Wikipedia
Where it lives
It inhabits vegetated ponds, marshes and lake shores.
Source: Wikipedia
What it eats
The caterpillars feed on species of the pondweed genus Potamogeton.
Source: Wikipedia
When you see it
Adults have been observed flying from May to September.
Source: Wikipedia
Where it comes from
It is found in North America, recorded from many U.S. states and Canadian provinces such as Illinois, Maine, Ontario and Quebec.
Source: Wikipedia
Where it is found in the US
Recorded in 26 of 51 states and DC. Most records: Minnesota, Wisconsin, Michigan, Vermont, New York, Ohio, Illinois, Massachusetts.
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
Source: GBIF
More photos
Questions people ask
When are adult chestnut-marked pondweed moths active?
Adults are on the wing from May through September.
Source: Wikipedia
Same family (Crambidae)
Box Tree MothCydalima perspectalisDamages trees, gardens or crops
Celery Leaftier MothUdea rubigalisDamages trees, gardens or crops
Elegant Grass-veneerMicrocrambus elegans
Hawaiian Beet Webworm MothSpoladea recurvalisDamages trees, gardens or crops
Garden Grass-veneerChrysoteuchia culmellaDamages trees, gardens or crops
Bluegrass Webworm MothParapediasia teterrellusDamages trees, gardens or cropsSources
- Wikipedia: https://en.wikipedia.org/wiki/Parapoynx_badiusalis
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.