Hickory Tussock Cocoon caused contact dermatitis

Subject: chrysalis
Location: Sidney, Maine
December 19, 2013 4:31 am
My friend’s son touched the cocoon and pretty quickly developed contact dermatitis. We’re wondering what butterfly/moth/something else? makes this cocoon.
Signature: Julia Hanauer-Milne

Possibly an Asp Cocoon
Hickory Tussock Moth Cocoon

Hi Julia,
It might not be possible for us to provide an accurate species identification based on your somewhat blurry image of a cocoon in a plastic bag, but we will try to provide you with some explanation.  Many furry caterpillars have utricating hairs that can cause irritation, especially in sensitive individuals.  Many of those caterpillars also use the hairs when spinning a cocoon to protect the pupa.  A chrysalis is the the pupa of a butterfly and this is definitely not a butterfly.  Furry caterpillars are generally moth caterpillars.  The Asp or Caterpillar of a Southern Flannel Moth is one that comes to mind, however, this species is generally found in Southern states.  BugGuide does have a photo of the cocoon and the pupa housed inside, and they look somewhat similar to your photo.  BugGuide reports the genus from as far north as New York, but BugGuide also provides this disclaimer:  “The information below is based on images submitted and identified by contributors. Range and date information may be incomplete, overinclusive, or just plain wrong.”
  We would not entirely discount that this cocoon belongs to an Asp, but considering your location, that is probably unlikely.  Bangor Daily News has an online article warning of the stinging Hickory Tussock Caterpillar, Lophocampa caryae, which states:  ” [Charlene] Donahue [forest entomologist with the Department of Conservation] advised people to leave the caterpillar alone because of the possibility of a reaction. They also should be cautious when cleaning up leaf litter on the ground since any hairs left behind by the caterpillar also could cause problems with some people, she added. She recommended that people wear gloves when cleaning up yards.  Some people aren’t bothered by the caterpillar but others could have a reaction that ranges from a mild to fairly severe rash, according to Donahue.  ‘It’s like poison ivy,’ she said.”   That article does not picture the cocoon.  The cocoon of the Hickory Tussock Moth pictured on BugGuide looks like a very close match to your cocoon, and considering the attention it has been getting in Maine lately, we believe that is a proper identification.

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