Pine False Webworm vs Light Cahill Mayfly

Side-by-side species comparison

Attribute Pine False Webworm Light Cahill Mayfly
Scientific Name Acantholyda erythrocephala Heptagenia solitaria
Order Hymenoptera Ephemeroptera
Family Pamphiliidae Heptageniidae
Size 10-15 mm (adult) 9-13 mm
Habitat Farmland Rivers & Streams
Diet Omnivores Omnivores
Regions Europe, North America North America
Conservation Not Evaluated Least Concern

Pine False Webworm

An invasive European sawfly that defoliates pines in North America. Unlike typical sawflies, larvae are solitary and spin silk tubes on branches.

💡

Did You Know?

Larvae feed inside silken tubes spun among the needles, unlike the gregarious feeding of most pine sawflies.

Light Cahill Mayfly

A pale-colored mayfly highly prized by fly fishers for imitating hatches. Nymphs prefer moderate current over gravel substrates.

💡

Did You Know?

The Light Cahill dry fly pattern, designed to mimic this species, has been used since the 1880s.