Hairy Dagger caterpillars

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American Dagger moth caterpillar (Acronicta americana) Philadelphia, USA © 2015 Maxine ShermanThe commonest hairy caterpillar being sighted from many American States at the moment seems to be the caterpillar of the American Dagger Moth, Acronicta Americana.

These wonderfully hairy caterpillars may look cuddly enough but their hairs have been known to cause rashes.

Some people seem to react more to the hairs of caterpillars than others, so to be on the safe side, it is advisable to avoid skin contact.

The colour can vary from pale yellow when young to almost white when fully grown as the images received from Maxine Sherman in Philadelphia and Linda Priesmeyer in Colorado show.

Identification of the American Dagger caterpillar

AmericanDagger moth caterpillar © 2015 Linda PriesmeyerUseful identifying features of these caterpillars are the two pairs of long black hairs that sprout out from the dense yellow/pale hairs on the upper half of their back nearest the head and the black tail-like spike.

Even when the caterpillar is rolled up these features can still be seen.

However, there are other caterpillar species such as the hairy Tussock Moth caterpillars that also have long black spiky hairs and dense hairs and tufts.

More hairy caterpillars can be seen on both the British caterpillar gallery and the American caterpillar gallery

American Dagger moth caterpillar (Acronicta americana) Philadelphia, USA © 2015 Maxine Sherman

American Dagger caterpillars feed on a variety of deciduous trees throughout much of North America and may be found in gardens.

When fully grown the caterpillars are frequently found wandering away from the food plant in search of somewhere to pupate.

Many thanks to Maxine and Linda for sharing their images.

Photos received may be added to the American caterpillar gallery with accreditation and copyright attached or featured in ‘latest sightings’ to help others with identification.

All images of USA caterpillars are welcome and can be emailed to