Currently viewing the category: "Asps and Flannel Moth Caterpillars"

Subject: Hairy Catepillar
Location: Berbice, Guyana
February 3, 2014 10:17 am
Found this hairy caterpillar on a garage near mango trees in Berbice, Guyana. The locals said it was very poisonous and said the hairs would cause swelling and a rash. They said those who have touched them need immediate medical attention. Not sure if it was true, but I still kept a safe distance. Could you identify what type of caterpillar this is? Thanks.
Signature: TKozza

Flannel Moth Caterpillar

Flannel Moth Caterpillar

Dear TKozza,
The locals were wise to warn you about this stinging Flannel Moth Caterpillar in the genus
Megalopyge.  It is our understanding that the sting can be quite debilitating.

Subject: Furry Slug Fish
Location: Houston, TX
November 4, 2013 3:56 pm
This furry slug like animal was attached to our trash can outside. Texas (Houston ) Fall early November weather. The animal is about 2” long and about 1/4- 1/2 ” diameter. Furr is a greyish salt an pepper tan color with a tail that is fish shaped but consisting of Furr.
Signature: -stumped in Houston



Hi stumped in Houston,
This stinging Southern Flannel Moth Caterpillar is commonly called an Asp.

Subject: Asps / Flannel Moth caterpillars…interesting colors
Location: Kyle, Texas
October 29, 2013 10:40 am
Greetings from Kyle, Texas!
This past weekend one of my kids found one of these asps crawling across our porch. It was a buff color and the largest I had ever seen. I captured it in a jar and then gave my kids (and the neighbor kids who were also there) a lesson that these are stinging caterpillars (in the glass jar we could actually see the stingers which are close to the feet) and never to be picked up or played with. We looked it up here at WTB of course, so everybody was well versed on these cute untouchables.
Then, this morning my youngest child who is four, came in saying that he’d found another one and sure enough he had found the darker one on our garage, very close to our rose bushes. On closer inspection, I found the orange one actually on the rose bushes. We decided to remove them and take some photos because of the color variations and also because they are very large…the jar lid they are occupying in the pics are three inches in diameter. To keep them and my kids safe, I put them in our compost pile where I put the other one from Saturday.
Thank you so much for your wonderful site!
Signature: M. family in Kyle



Dear M. family,
Thanks so much for sending us your photo of the color variations in Asps, the stinging caterpillar of the Southern Flannel Moth.  We are happy to hear our site was helpful.  We are postdating your submission to go live in early November while we are out of the office.

Subject: caterpillars
Location: Gueydan La. 70542
October 5, 2013 8:03 am
Hello, i found these caterpillars on my back porch in Gueydan La. 70542. on 10/5/2013. They look like they might be a moth caterpillar but i can not find the right I.D. on your sight, i am sure you have it, but i can not find it. You have an awsome site , i have i.d. several bugs and butterflies…. Thank you for your time and effort! I always recommend this site to my freinds and family.
Could you i.d. these caterpillars for me, i will send several pictures to you.
Thanks for your time….
Signature: brittany



Hi Brittany,
These are Southern Flannel Moth Caterpillars,
Megalopyge opercularis, and because they are stinging caterpillars, they are sometimes called Asps, especially in southern states.  They are also known as Puss Caterpillars according to BugGuide.



Thank you so much for the quick response and your time, i now have 4 Asps on my back porch..
Thanks for the warning that they sting.
Thank you, Brittany

Location: northeast alabama
August 7, 2011 7:05 pm
Found this on a wooden rockin chair. It looks like a little ball of fur
Signature: thanks

Stinging Asp

Handle the stinging Asp with care, or better yet, not at all.  The Asp or Puss Moth Caterpillar is the immature form of the Southern Flannel Moth, and it is one of North America’s stinging caterpillars.  The sting is reported to be quite painful.

The Big 5 are five potentially dangerous bugs.  Though we do not by any means endorse any wholesale extermination of the creatures on this list, we would caution all of our readers to treat these guys, though more are actually gals, with the utmost respect.  They will all bite and or sting, and they are all venomous.  There are no doubt deaths that can be associated with most if not all of them, though we would also add that the death to survival rate is very low.  We would now like to introduce you to The Big 5, though we expect that there will eventually be more than five creatures so tagged.

#1:  Tarantula Hawk
It’s really big, it flies, it announces itself with a buzz that sounds like a small airplane, and it advertises with aposematic coloration (orange and black), an it has a really big stinger, at least the female does.  There are not many creatures that can take on a Tarantula and win, but the Tarantula Hawk seems to have no problems perpetuating the species by feeding upon the meat of a tarantula during its formative period.

Tarantula Hawk

Update:  August 9, 2011
We just received this comment on a Tarantula Hawk Posting:
“Went back to the location where I took the Tarantula Hawk Pic hoping to see a bit more. Saw one dragging a male tarantula along and got to close. You are correct they have a very painful sting, got me on the hand twice. I dropped the camera went back to get it and got zapped again, this time on my calf. Being handicapped and unable to run, though I did a fairly good impression of all three stooges melded into one trying to make my escape, I will take appropriate measures next time I try to get that close to something and its food. I almost had to have my ring cut off my hand it swelled up so fast. The only pics taken that day were of me after a shot of benadryl, not so hilarious pics taken by my ‘firends’ while I was passed out from the benadryl and drooled on the sofa. Those stings are about on par or worse with the few scorpion stings I have had in the past. A regular wasp or bee sting pales in comparison. I am just glad that I did not have a very severe allergic reaction. So be warned do not attempt to get to close to these flying strike force wasps once they have their prey in ‘hand’.”

#2:  Bark Scorpion
Bark Scorpions in the genus
Centruroides are among the most dangerous North American Scorpions.  Here is what BugGuide has to say about the sting of several species of Bark Scorpions:  “The sting of most scorpions is not serious and usually causes only localized pain, some swelling, tenderness and some discoloration. Systemic reactions to scorpion stings are rare.
The sting of one of our scorpions, however, Centruroides sculpturatus(until recently thought to be the same as Centruroides exilicauda), the Arizona Bark Scorpion, can be fatal. Most healthy adults are not at significant risk- only children, with their smaller body size, are in danger (treatment with antivenom has pretty much put a stop to deaths where available, but bark-scorpion stings should still be taken very seriously). The site of the sting does not become discolored.  Another scorpion known to have an intense sting is Centruroides vittatus, but no deaths have been attributed to it directly.”

Bark Scorpion

#3:  Red Headed Centipede
Most of our reports of Red Headed House Centipedes,
Scolopendra heros, come from Oklahoma and Texas and they are reported to grow as large as 8 inches in length.  All Centipedes have venom, but the Tropical Centipedes in the order Scolopendromorpha are generally considered the ones with the most virulent venom.  There are several subspecies of Scolopendra heros, and there are also numerous color variations.  Not all individuals have a red head.

Red Headed Centipede

#4: Black Widow
With her glossy black body and red hourglass marking, the Black Widow Spider is an icon of warning coloration.  The venom of the Black Widow is a powerful neurotoxin, and according to Emedicine Health, it is described as:  “Local pain may be followed by localized or generalized severe muscle cramps, abdominal pain, weakness, and tremor. Large muscle groups (such as shoulder or back) are often affected, resulting in considerable pain. In severe cases, nausea, vomiting, fainting, dizziness, chest pain, and respiratory difficulties may follow.  The severity of the reaction depends on the age and physical condition of the person bitten. Children and the elderly are more seriously affected than young adults.   In some cases, abdominal pain may mimic such conditions as appendicitis or gallbladder problems. Chest pain may be mistaken for a heart attack.   Blood pressure and heart rate may be elevated. The elevation of blood pressure can lead to one of the most severe complications.   People rarely die from a black widow’s bite. Life-threatening reactions are generally seen only in small children and the elderly.”


Black Widow

#5:  Cowkiller
The Cowkiller is a female Velvet Ant, a flightless wasp that is alleged to have a sting painful enough to kill a cow.


Runner-Up:  Creechie
Unlike the Big 5, the runner-up, the Paederus Rove Beetle, does not bite or sting, but it can cause an horrific skin reaction by merely touching it.  Most of our reports of Creechie (African name) where it is also called the Acid Bug, AKA Cari-Cari in Malaysia, Potó in Brazil  and potentially Bicho de Fuego in Panama, come from tropical countries.  Though most of our reports of Paederus Rove Beetles have come from Africa, Asia and South America, we did receive a report from Arizona two years ago and one from West Virginia in 2008 in December which we imagine means Creechies can survive the cold.  Paederus Rove Beetles also sport aposematic coloration.

Creechie in Camaroon or Cari-Cari in Malaysia

 Runner-Up:  Muskmares
Walkingsticks in the genus Anisomorpha are commonly called Two Striped Walkingsticks or Muskmares. The second common name is due to the frequency that these Walkingsticks are found in the act of mating.  These Muskmares are capable of spraying a noxious substance with great accuracy over some distance, and they are good at hitting the eyes of a potential threat.  The effects wear off shortly, but will cause the eyes to water and blur as well as sting.  The latest information posted to BugGuide has the potential for harm as more serious:  “Members of this genus can deliver a chemical spray to the eyes that can cause corneal damage.” 

Mating Muskmares

Update:  August 10, 2014
Runner-Up:  Asp
A comment today has prompted us to add the Asp, or Southern Flannel Moth Caterpillar, to The Big 5 tag.  This stinging caterpillar is reported to have a very painful sting.

Asp or Southern Flannel Moth Caterpillar

Asp or Southern Flannel Moth Caterpillar