Currently viewing the category: "Asps and Flannel Moth Caterpillars"
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Subject: Caterpillar?
Location: Southeast Missouri
August 1, 2017 2:50 pm
My cousin found this in her bed one evening! She had a few spots on her arm and leg that stung. Could this be a type of stinging caterpillar?
Signature: Brittany

White Flannel Moth Caterpillar

Dear Brittany,
This is a White Flannel Moth Caterpillar and they do sting.  Here is a BugGuide image for comparison.  According to BugGuide, the caterpillars feed on “A variety of hosts reported including black locust, hackberry and redbud.”  Are any of those trees growing near your cousin’s bedroom?

White Flannel Moth Caterpillar

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Subject: Black waved flannel moth
Location: Fredericksburg, Virginia
June 30, 2017 12:46 am
I’m pretty certain that these photos are of the Black Waved Flannel Moth (checking against bug guide)(and reading that you have had endless photos of them). …I got no absolute confirmation from Bugguide but there were many photos of identical moths. The information I can’t seem to find, is what relationship these moths have to the Puss Caterpillar. They seem to be separate ….there are the megalopygea opercularis and then there are the species Lagoa crispata. Both Flannel Moths? Similar looking caterpillars?.
And the Puss Caterpillar is VENOMOUS but I can’t find information on how venomous the Lagoa crispata is. Or the specific caterpillar. The internet is conflicting. Are they venomous and are they AS venomous?
Signature: Susan Warner

Black Waved Flannel Moth

Dear Susan,
All the images you provided are details.  We wish you had provided a standard dorsal view of the entire moth.  We believe your identification of the Black Waved Flannel Moth is correct, and the antennae indicate this is a male moth.  BugGuide does indicate:  “Caution, Hairs on caterpillar highly irritating, as in all of this family!”  So, the family Megalopygea includes both
Lagoa crispata and Megalopyge opercularis, but they are classified in different genera within the family.  According to an article on the Asp, Megalopyge opercularis, by David M. Eagleman on EaglemanLab:  “Envenomation from the spines of the caterpillar causes severe pain, burning, swelling, nausea, abdominal distress, and headache. … The best known venomous caterpillar in the American south- west is the puss moth caterpillar, Megalopyge opercularis, commonly called an asp, wooly asp, Italian asp, opossum bug, wooly slug, and el perrito. It is considered one of the most toxic caterpillars in North America.”  We agree with you that the two caterpillars look very similar, and it is entirely possible that some Asp postings on our site are misidentified, and are actually the caterpillars of the Black Waved Flannel Moth.  Regarding the relative venomousness of the two species, we cannot provide you with a scale or data, but we do know that irritation and reactions to stings and bites from insects vary from person to person.  Some folks are highly allergic to the sting of a Honey Bee while other folks are barely affected at all beyond the initial pain of the sting.  Some folks have tremendous reactions to the bite of a Lacewing, while others are not affected at all.  We would urge you to refrain from handling both species, though again, distinguishing between the two might be difficult.  It is also possible that the sting of the Black Waved Flannel Moth caterpillar has not been studied as extensively as has the Asp.  Of the entire Flannel Moth family Megalopygidae, the Auburn Agriculture page on Stinging Caterpillars states:  “Flannel moth caterpillars, like slug caterpillars, do not exactly fit the description of the typical lepidopterous larva. Structurally they differ in having seven pairs of prolegs rather than five (or less) pairs common to typical caterpillars. Most are clothed with fine, long, silky hairs. There are no conspicuous large, threatening, bristle-bearing “horns” to warn of danger; however, concealed within the hairy coats are venomous setae capable of producing severe reactions.”  While the Black Waved Flannel Moth is not discussed in the article, Auburn Agriculture does clearly state:  ”  Puss Caterpillar (Megalopyge opercularis) The puss caterpillar (the adult is called southern flannel moth) is our most ‘dangerous’ stinging caterpillar. Contact may produce severe reactions including: intense burning and nettling of the skin; severe pain; reddening and inflammation; development of pustules and other lesions; numbness; swelling, which may sometimes be extensive; and nausea. Pain may persist from one to twelve or more hours. In some instances, victims have required medical attention. The larva is urticating in all stages, but severity of the reaction is generally proportional to size. Also, newly molted skins retain stinging capabilities.”  There you have it.  According to Auburn Agriculture, the Asp is “our [North American] most ‘dangerous’ stinging caterpillar.”

Subject: supplement photo (dorsal)
Location: Frederericksburg
June 30, 2017 8:19 pm
I have a dorsal view of the moth…better overall….not just the detail….of the Black Waved Flannel Moth photo i sent, to help make an ABSOLUTE identification.
It seems that both the puss variety and this one are all something to avoid. I wanted to know if seeing this moth might indicate puss or super venomous caterpillars in the vicinity. A friend in the southwest once had to go to the ER after leaning on a puss caterpillar.
Subject: Black waved flannel moth
Location: Fredericksburg, Virginia
June 30, 2017 12:46 am
Signature: Susan Warner

Black Waved Flannel Moth

Dear Susan,
Thank you for sending in a supplementary dorsal view of a Black Waved Flannel Moth.

What's That Bug? does not endorse extermination

Subject: Caterpillar ID
Location: Northern Virginia
January 5, 2017 7:50 am
Found these in early fall in Northern Virginia. Can’t find a picture of it anywhere. Any idea what it is?
Signature: Chad

White Flannel Moth Caterpillars

Dear Chad,
You should handle these White Flannel Moth Caterpillars,
Norape ovina, with caution because according to BugGuide:  “Caterpillar has stinging spines.”

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Subject: strange catapillar
Location: outside Houston
November 19, 2016 12:36 pm
Attached are a couple pics of a catapillar that I have never seen before outside of Houston, TX. My wife has been bitten/stung by these twice in the last 2 weeks. They are very slow moving. It is a very painful bite/sting that lasts several days and leaves a good size welt. I have lived in this house for 15 years and never seen one. This fall alone I’ve seen about a dozen.
Signature: at your descretion

White Asp

White Asp

The Asp is the stinging caterpillar (which you already learned) of the Southern Flannel Moth or Puss Moth.  Asps come in a variety of colors, but white Asps do not seem as common as other colors like orange and brown.

White Asp

White Asp

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Subject: Cuckoo for caterpillars (Food Chain)
Location: Louisa Co., Virginia, USA
August 17, 2016 10:24 am
I have a 9-year-old honeylocust which this year has the most glorious infestation of some apparently delicious caterpillars. I am an avid birdwatcher and have contented myself with mostly listening for the shy, elusive cuckoos that appear in my yard every year. However, for the past week they have not been able to stay away from this tree and the buffet the caterpillars are providing – as many as 3 cuckoos hanging around gorging themselves just outside my door. I’m not concerned about the tree – just a bit of minor defoliation, and it’s late in the season – but I sure hope that whatever bug this is decides to come back from now on so I can get such fantastic views of yellow-billed cuckoos!
Signature: Winston B

White Flannel Moth Caterpillar

White Flannel Moth Caterpillar

Goodness, Gracious Winston,
This one proved to be a far greater challenge to us than we anticipated.  We recall having identified this distinctive caterpillar species in the past, and we were relatively certain it was a Flannel Moth Caterpillar, so we searched our own archive.  We looked at hundreds of old postings, beginning with Asps and Flannel Moth Caterpillars, but we could not locate it.  We eventually found it on Walter Reeves Venomous (Poisonous) Caterpillars site where it is identified as a White Flannel Moth Caterpillar.  We then returned to our own site, but the most recent posting we had of a White Flannel Moth Caterpillar,
Norape ovina, was 2007, and that predated our site overhaul and recategorization method.  According to BugGuide:  “Caterpillar has stinging spines” but obviously, your Cuckoos are unaffected by the spines or venom.  BugGuide also notes:  “Species name ovina is Latin, meaning ‘of or like sheep'” and we suspect that might be a reference to their group grazing behavior.  We love your Food Chain images.

Cuckoo Eats White Flannel Moth Caterpillars

Cuckoo Eats White Flannel Moth Caterpillars

What's That Bug? does not endorse extermination

Subject: Insect Case Identification
Location: Gulf Shores, Alabama
March 17, 2016 10:17 am
Attached is a picture of an insect case found on some small oak trees. We would like some identification of the insect that would deposit such a case.
Signature: Gulf State Park Nature Center

Cocoons

Cocoons

We have to call these Cocoons because they look like larvae made them before pupating and eventually emerging.  We will research in the morning.

I have been searching too.  Could it be a Megalopyge opercularis (southern flannel moth cocoon)?
Thanks,
Kelly Reetz
Naturalist – Gulf State Park

Hi Kelly,
We received a comment indicating the cocoons belong to the Southern Flannel Moth.  This BugGuide image supports that ID.  They appear to be empty, indicating the adult Southern Flannel Moths have already emerged.

What's That Bug? does not endorse extermination