Herpetogramma aeglealis

(Walker, 1859)
Serpentine Webworm

Sort #: 1556 | P #: 801017 | MPG #: 5280
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Larval feeding type: Frond tier
Larval substrate: Various fern species, incl. Polystichum acrostichoides (Christmas Fern), Osmunda (Royal Fern). Reportedly also many other herbaceous plants.
Phenology: Adult: 6/25 to 10/28 (121 records)

Comment: Dark specimens of H. aeglealis can be distinguished from F. sphingealis by the presence of a pale patch in the fringe at the forewing tornus.

Status in MA (automated assessment): Widespread, very common
Status in N. America: Native
MA Endangered Species Act status: None
First Year Reported: 1901
Last Year Reported: 2026

Distribution by County: Berkshire, Hampden, Hampshire, Franklin, Worcester, Middlesex, Essex, Suffolk, Norfolk, Bristol, Plymouth, Barnstable, Dukes, Nantucket
Number of Records: 138