Herpetogramma theseusalis

(Walker, 1859)

Sort #: 1564 | P #: 801028 | MPG #: 5279
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Larval feeding type: Frond tier
Larval substrate: Various fern spp., especially Thelypteris palustris (Marsh Fern), Matteuccia struthiopteris* (Fiddlehead Fern), Osmunda* (Royal Fern), Woodwardia* (Chain Fern)
Phenology: Adult: 6/13 to 9/18 (40 records)

Status in MA (automated assessment): Widespread, very common
Status in N. America: Native
MA Endangered Species Act status: None
First Year Reported: 1934
Last Year Reported: 2026

Distribution by County: Berkshire, Hampshire, Franklin, Worcester, Middlesex, Suffolk, Norfolk, Bristol, Plymouth, Barnstable, Dukes, Nantucket
Number of Records: 48