Bug FAQSweetfern Geometer Moth
Cyclophora pendulinaria · Order: Lepidoptera · Family: Geometridae
Also called: Pearly-Gray Wave, Sweet Fern Geometer, Sweetfern Geometer, Sweetfern Mocha
The moth has a wingspan of about 17 to 26 mm and lives in moist forests across much of North America. Its caterpillars eat the leaves of sweetfern (Comptonia) and alder (Alnus) plants. Adults are active from April through October.
Source: Wikipedia
Size
The wingspan ranges from 17 to 26 mm.
Source: Wikipedia
Where it lives
It lives in moist or mesic forest habitats.
Source: Wikipedia
What it eats
Larvae feed on the leaves of sweetfern (Comptonia) and alder (Alnus) species.
Source: Wikipedia
Life cycle
Adults have been recorded on the wing from April to October.
Source: Wikipedia
When you see it
The flight period spans April through October.
Source: Wikipedia
Where it comes from
Its range covers much of North America, from eastern Canada to the Pacific coast and down to the southeastern United States.
Source: Wikipedia
Where it is found in the US
Recorded in 32 of 51 states and DC. Most records: Massachusetts, Maine, Vermont, New York, Connecticut, New Hampshire, Pennsylvania, Michigan.
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
More photos
Questions people ask
When can I see these moths?
Adults are active from spring through fall, roughly April to October.
Source: Wikipedia
Same family (Geometridae)
Willow BeautyPeribatodes rhomboidaria
Pale BeautyCampaea perlataDamages trees, gardens or crops
Large Lace-border MothScopula limboundataDamages trees, gardens or crops
Riband WaveIdaea aversata
Yellow Shell MothCamptogramma bilineata
Large Maple Spanworm MothProchoerodes lineolaDamages trees, gardens or cropsSources
- Wikipedia: https://en.wikipedia.org/wiki/Cyclophora_pendulinaria
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-22 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-22.