Flannel moth caterpillars, also known as puss caterpillars or asp caterpillars, are fascinating creatures with unique characteristics. These caterpillars are known for their distinct appearance, which includes thick, fluffy setae that resemble a pussycat’s fur, giving them the name “puss caterpillars” Puss Caterpillar.
In this article, we will explore various aspects of the flannel moth caterpillar, such as its life cycle, habitat, and interaction with the environment. As we delve further into these intriguing creatures, you’ll come to appreciate the complexities of their existence and their importance in the natural world. Some key points to remember about flannel moth caterpillars include:
- Potent stings that can cause pain and irritation
- Notorious for infesting shade trees and shrubbery Asps and Other Stinging Caterpillars
- Adult moths with fluffy, wavy, flannel-like scales
- Cocoons that remain on plants even after the adult emerges Southern Flannel Moth
Size and Color
The flannel moth caterpillar, also known as Megalopyge opercularis, is recognizable by its distinct appearance. The caterpillar features:
- A hairy texture that looks like soft fur
- A gray, yellowish, or brownish color
Adult flannel moths are chunky-bodied, with their bodies, legs, and wings covered in fluffy hair, giving it a fluffy appearance 1(https://education.mdc.mo.gov/discover-nature/field-guide/flannel-moths).
|Flannel Moth Caterpillar
|Adult Flannel Moth
|Caterpillars can reach about 1¼ inches long 2(https://mdc.mo.gov/discover-nature/field-guide/flannel-moths)
|Gray, yellowish, or brownish
Beneath their soft, fur-like appearance, flannel moth caterpillars possess venomous spines that can cause painful reactions. Contact with these spines may lead to symptoms such as:
- Intense pain
It’s essential to exercise caution and avoid handling these caterpillars to prevent the harmful effects of their venomous spines.
Habitat and Distribution
The habitat of the flannel moth caterpillar, also known as the puss caterpillar, spans across various regions in North America. These caterpillars can be found in states like Texas, Florida, and Arkansas, as well as along the east coast.
During the summer and fall months, flannel moth caterpillars are more active and easier to spot. They typically inhabit trees and bushes in these areas, feeding on their host plants.
Some common host plants include:
- Oak trees
- Elm trees
- Wild plum
In comparing the distribution of flannel moth caterpillars in various regions, we can observe the following distinctions:
By understanding the habitat and distribution of flannel moth caterpillars, you can observe and appreciate these fascinating creatures in their natural environment. Just remember to be cautious, as their stinging hairs can cause painful reactions.
- Megalopyge opercularis, also known as the southern flannel moth
- Eggs laid in clusters
The female southern flannel moth lays her eggs in clusters on host plants. The eggs are small, round, and have a light-colored appearance.
- Venomous puss caterpillars
- Densely covered with fine hairs
The larval stage of the flannel moth is the well-known puss caterpillar. These caterpillars have a teardrop shape and are densely covered with fine gray or tan hairs that taper into a tail. They have a distinctive crest of rusty hairs along their backs and tufts of whitish hairs on their sides.
- Tough cocoons
- Remain on host plants
The pupal stage takes place within a tough cocoon, which remains on the host plant even after the adult emerges. These cocoons provide protection for the developing flannel moths.
- Small, hairy moths
- Wingspan of 1-1.5 inches
After emerging from the pupae, the adult southern flannel moths are small and hairy, with a wingspan measuring between 1 and 1.5 inches. The females are typically larger than the males. Their front wings are yellow, while their hind wings are creamy yellow. The moths’ bodies are covered with thick, fur-like hairs that are yellow to orange in color.
Diet and Damage
The flannel moth caterpillars, also known as puss caterpillars, primarily feed on a variety of plants and trees. Their diet includes oaks, deciduous trees, shrubs, and other leafy plants. These caterpillars are a species of concern due to their potential to cause damage to their host plants.
One reason for the damage caused is the caterpillars’ voracious appetite for leaves. They can strip a plant or tree of its foliage in a short period. This defoliation can weaken the host, making it susceptible to diseases and other pests.
Here’s a comparison of the trees and plants most commonly affected by flannel moth caterpillars:
|Susceptibility to Damage
Some notable aspects of flannel moth caterpillars include:
- They are covered in thick, fluffy fur-like setae
- Their potent sting can cause pain and discomfort to humans
- Adults, called flannel moths, are covered in wavy, flannel-like scales
Keep in mind that despite their destructive potential, flannel moth caterpillars play an essential role in the ecosystem, providing a source of food for predators like birds and other insects.
Stinging and Medical Implications
Symptoms and Risks
The sting of a flannel moth caterpillar can cause a range of symptoms, including:
- Burning sensation at the site of the sting
- Swelling and itching around the affected area
- Development of a rash called erucism, which can be painful1
- Nausea or abdominal pain in some cases
A more severe allergic reaction may occur in some individuals, presenting symptoms such as:
- Difficulty breathing
In these cases, it is crucial to seek immediate medical attention.
Treatment and Care
Here are some recommendations for treating the sting of a flannel moth caterpillar:
- Remove any visible spine remnants by using adhesive tape on the affected area2.
- Apply a cold compress to reduce pain and swelling.
- Use over-the-counter antihistamines or corticosteroids to manage itching2.
- If symptoms worsen or persist, consult a physician for possible diagnosis of dermatitis or other complications.
|Cold compress, pain relievers
|Cold compress, antihistamines, corticosteroids
|Consult a physician if severe
|Seek immediate medical attention
Puss caterpillars, also known as flannel moth caterpillars, have several natural predators. Despite their potent stings, some predators still feed on them.
Insects: Predatory bugs, such as lacewings and lady beetles, feed on flannel moth caterpillars in their early stages of development.
Spiders: These predators can catch caterpillars in their webs or hunt them down.
Here’s a brief comparison of these predators in relation to flannel moth caterpillars:
|Attack caterpillars in early stages of growth
|May not target fully grown caterpillars
|Use webs to catch or actively hunt caterpillars
|Can be deterred by the caterpillar’s sting
In conclusion, flannel moth caterpillars may have a defense mechanism in their sting, but they are still susceptible to predation from insects and spiders in their natural habitat.
Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.
Letter 1 – Flannel Moth Caterpillar
Unknown caterpillar from Peru
May 22, 2010
I found this caterpillar on a walk through the Peruvian Amazon. It was about 2.5-3 inches long. I tapped the branch it was on to try and collect it, but some of the hairs started coming off so I decided to just take a picture.
Quincemil, Peru 640-800m in SE Peru
In North America, there is a group of caterpillars in the Flannel Moth family Megalopygidae (which is represented on BugGuide) that are commonly called Asps. Asps, which are also known as Puss Caterpillars, are stinging caterpillars. We suspect your specimen is closely related to the Southern Flannel Moth, Megalopyge opercularis which is profiled on BugGuide.
Letter 2 – Mysterious Brazilian Caterpillar
what’s that bug
Hello! My name is José Antônio. I live in Brazil. I found this caterpillar (Megalopygidae) in a orange tree. Can you help me to identify the species? Thank you very much.
Hi José Antônio,
Sorry to have taken so long, but we have tried to contact other people to get you an identification. Sadly we are unable to help you. You probably know much more about your native species than we do since you have identified it as a Megalopygidae. Our members of that group are known as Puss Moths. The caterpillars often have poison spines and are called Asps locally, especially in Texas. Good luck with a positive identification. Please keep us informed as to what you find out. You can always raise the caterpillar since you know its food plant and then see what type of moth emerges. Have a great day. Daniel
Letter 3 – White Flannel Moth Caterpillar
white flannel moth caterpillar
I believe we found a White Flannel Moth Caterpillar while hiking the Cumberland Trail near Crossville, TN. One of our group got a bit of a sting when brushing past this colorful caterpillar. I would like to confirm the ID if possible.
You are absolutely correct. This is a White Flannel Moth Caterpillar, Norape ovina, and the sting is quite painful.
Letter 4 – White Flannel Moth Caterpillar
My boyfriend found this caterpillar in his front yard in Southern Maryland. When he found this caterpillar(S) he was cutting the grass on a riding lawn mower and drove through a Red Bud Tree and out of the branches he started to get sensations in 3 or 4 spots on his body, on the side of his belly, arm and leg. Then there is a stinging burning sensation. We have searched the internet with no avail. Can you tell us what kind this is? Thanks
Steven & Sheree
Hi Steven and Sheree,
We did not recognize your caterpillar, and we were intrigued at your lack of luck in researching its identity. Searching the internet to no avail, in our minds, means that time and effort were spent. We simply typed caterpillar and redbud and googled, and the immediately found two sites, Stinging Caterpillars of Alabama, and Stinging Caterpillars on Shade and Ornamental Trees, that identified your caterpillar as a White Flannel Moth Caterpillar, Norape ovina, whose primary host is the redbud tree.