Slug Caterpillar: Key Facts and Essential Tips

Slug caterpillars can easily catch your attention due to their exquisite appearance. Contrary to their name, these creatures are not actually slugs but rather the larvae stage of certain moth species. These caterpillars are colorful, flattened, and come in various shapes and sizes, making them a fascinating subject of study.

As you explore the world of slug caterpillars, you’ll come across their intriguing features like the crowned slug caterpillar, known for its pastel green color, beautiful plumes of stinging hairs, and captivating patterns. However, remember that these insects should be admired from a distance, since touching them can lead to painful stings.

Understanding the life cycle and habitat of slug caterpillars is essential as it helps with their proper identification. They go through metamorphosis, transforming from a feeding larval stage to adulthood, when they become furry, heavy-bodied moths. With more than 20 species within this family, these caterpillars can be found in various climates worldwide, including tropical regions.

Understanding Slug Caterpillars

Slug caterpillars belong to the family Limacodidae and are quite different from other caterpillars. They get their name from their resemblance to slugs, with a flattened, oval body and reduced legs.

These unique insects have unusual features. For example, their legs lack tiny hooks found in most caterpillars, giving them a slug-like appearance. They also have stinging hairs on their bodies, which can cause irritation when touched.

Some notable species include the saddleback caterpillar and the crowned slug caterpillar. The saddleback caterpillar has urticating hairs on four prominent knobs at the front and rear, while the crowned slug caterpillar has stinging hairs around its perimeter and less conspicuous hairs on top.

Here are some key features of slug caterpillars:

• Flattened, oval body
• Reduced legs
• Stinging hairs
• Wide variety in colors and patterns

Slug caterpillars are not only fascinating insects to observe, but they also play a role in the ecosystem. Just like other insects, they are part of the food chain and serve as a valuable food source for predators such as birds and other insects.

When encountering slug caterpillars, it’s important to handle them with care as their stinging hairs can cause skin irritation. However, with proper precautions, you can observe their unique beauty and behaviors, appreciating their place in the diverse world of insects.

Physical Appearance

Color and Texture

Slug caterpillars come in various colors, including shades of brown, green, and white. These colors can help them camouflage with their surroundings. They also have various textures on their bodies, such as spines and hairs.

For instance, you might spot:

• Brown slug caterpillars with stinging spines.
• Green ones with soft bristles.
• White ones with distinct horns.

Special Features

Slug caterpillars have several unique features that set them apart from other types of caterpillars. Some of these features are:

• Stinging Spines: Many slug caterpillars have rows of sharp, venomous spines on their bodies that can cause painful reactions if touched. Beware of these if you come across one.
• Horns: Some species feature horn-like structures to ward off predators.
• Suckers: Instead of regular legs, slug caterpillars have suckers, which help them move in a slow, slug-like fashion.

Size of Slug Caterpillars

Slug caterpillars vary in size, but most of them are relatively small, ranging from a few millimeters to a couple of centimeters in length. The size of the caterpillar can depend on factors such as age, species, and environmental conditions.

Remember to always observe these fascinating creatures from a distance to avoid getting stung.

The Lifecycle of Slug Caterpillars

The Larval Stage

The larval stage of slug caterpillars starts with them hatching from eggs. At this point, they are small and feature pastel green coloration. These caterpillars have:

• Flattened, oval-shaped bodies
• Plumes of stinging hairs around the perimeter
• Shorter, less conspicuous hairs on top
• Three pairs of legs directly behind the head

As they feed and grow, the larvae develop distinctive markings and color patterns specific to their species.

The Pupal Stage

After the larval stage, slug caterpillars prepare to pupate. During this stage, they:

• Stop feeding
• Find a suitable place for transformation
• Spin cocoons for protection

Inside the cocoon, the slug caterpillar undergoes a significant metamorphosis. Its body changes as organs and structures reorganize to form an adult moth.

The Adult Stage

The final stage in the life cycle of slug caterpillars is the adult stage. In this stage, the insect becomes a fully-formed moth. Some characteristics of the adult moth include:

• Wings with distinct markings and coloration
• Grayish-white setae on the wings and upper legs
• Faint black zigzags and narrow black rings on the wings

Once they emerge from their cocoons, these moths have two main objectives: reproducing and laying eggs. The cycle then starts all over again as the next generation of slug caterpillars begins to hatch and grow.

Varieties of Slug Caterpillars

Slug caterpillars belong to the slug caterpillar family and are known for their unique appearance resembling snails without shells. Many of these caterpillars have venomous spines, which can cause painful stings similar to a bee sting. Here, you will learn about four varieties of slug caterpillars: Saddleback Caterpillar, Monkey Slug, Crowned Slug Caterpillar, and Spiny Oak Slug.

Saddleback Caterpillar

The Saddleback Caterpillar (Acharia stimulea) is a well-known member of the venomous caterpillars category due to its distinct appearance and stinging hairs. You can identify this caterpillar by its:

• Green “saddle” marking on the back
• Prominent knobs with stinging hairs
• Urge to avoid touching them as they can cause skin irritation

Monkey Slug

The Monkey Slug (Phobetron pithecium), also known as the Hag Moth, is another interesting variety. You may recognize the Monkey Slug by:

• Its hairy, brown appearance
• Six leg-like protrusions
• Resemblance to a tiny monkey

Crowned Slug Caterpillar

The Crowned Slug Caterpillar (Isa textula) is considered one of the most exquisite varieties due to its unique features. These caterpillars have:

• Flattened, oval shape
• Pastel green color
• Plumes of stinging hairs around the perimeter

Spiny Oak Slug

Finally, the Spiny Oak Slug is another distinct variety, commonly found on oak and other hardwood trees. The Spiny Oak Slug can be identified by:

• Bright green color
• Rows of yellow and white stinging spines
• Typical feeding habits on oak tree leaves

While each variety of slug caterpillar is unique in its own way, they all share certain traits, such as stinging hairs and unusual appearances. It’s important to keep in mind that touching these caterpillars may result in skin irritation and pain, so always admire them from a safe distance.

Environmental Interactions

Plant Relationships

Slug caterpillars can greatly impact the plants they feed on. Trees such as oak, elm, cherry, hickory, and maple species can become host plants for these caterpillars. They can also affect flowers and other garden plants. As a gardener or farmer, it’s crucial to keep an eye out for these caterpillars to ensure the health of your plants.

Some common host plants for slug caterpillars include:

• Oak trees
• Elm trees
• Cherry trees
• Hickory trees
• Maple trees

Geographic Distribution

Slug caterpillars can be found in various parts of the world but are mainly found in North America. Their range spans from Missouri to Virginia and down to Texas. It’s important to be aware of their presence in your region to take appropriate action if needed.

For example, some locations where slug caterpillars can be found include:

• Missouri
• Virginia
• Texas

Climate Effects

Climate change may influence the distribution and behavior of slug caterpillars. Warmer temperatures can increase the range of these insects, potentially introducing them to new areas where they could pose a risk to plants and gardens.

By being aware of slug caterpillars and their environmental interactions, you can better protect your plants, trees, and gardens from potential damage they may cause.

Slug Caterpillars and Humans

Sting and Symptoms

When you encounter a slug caterpillar, be cautious, for they have venomous spines that can deliver a painful sting. The sting might result in symptoms like itching, swelling, and rash. In some cases, the pain can be severe, leading to vomiting, shock, and even an allergic reaction. It’s essential to pay attention to these symptoms and seek medical attention when necessary.

Slug caterpillars are slow-moving, so it’s unlikely for them to aggressively approach you. However, it’s still wise to steer clear of these poisonous caterpillars if you come across them in nature.

Control and Prevention

To prevent slug caterpillars from becoming an issue in your garden or home, you can take a few simple steps:

• Regularly inspect your plants and trees for signs of slug caterpillar presence.
• Remove any caterpillars you find by using gloves or other protective gear to prevent stings.
• Introduce natural predators, such as birds or insects, who prey on slug caterpillars.
• Use safe and environmentally friendly pesticides when necessary.

Keep in mind that some slug caterpillars are harmless, but it’s always better to practice caution and control when you suspect a poisonous variety is nearby.

Treatment

If you do experience a sting from a slug caterpillar, the following treatments may alleviate the symptoms:

• Gently remove any spines from your skin using a piece of adhesive tape.
• Wash the affected area with soap and water to prevent infection.
• Apply a cold compress to reduce swelling and discomfort.
• Over-the-counter pain relievers, anti-itch creams, and antihistamines may help to control symptoms.
• Seek medical help if you are experiencing severe pain or symptoms worsen.

Remember, slug caterpillars are part of nature’s ecosystem, so it’s essential to understand and respect their presence. Stay vigilant, take precautions, and know how to handle a potential sting from these creatures. Be careful when you encounter them, and always prioritize your safety.

Conclusion

In summary, Slug Caterpillars are fascinating creatures with unique appearances and behaviors. They can be easily identified by their flattened, oval shape, and pastel green color with plumes of stinging hairs around the perimeter. Remember, some species like the crowned slug caterpillar are known for their exquisite beauty.

Be cautious when handling these interesting caterpillars as their stinging hairs can cause discomfort or irritation. In addition, be aware that the adult moth stage differs in appearance, often showcasing bright colors and patterns.

If you encounter a Slug Caterpillar in the wild, take a moment to appreciate its beauty and observe its behavior. But, always remember to give it adequate space and respect as it’s a vital part of our ecosystem. Enjoy your encounters with these remarkable creatures and the wonders of nature that they represent.

Reader Emails

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 – Stinging Slug Caterpillars from South Africa: Latoia vivida

 

Subject: Green Spiky hair catepillar
Location: Johannesburg suburbs, South Africa
January 10, 2015 2:28 am
Hi There,
I have lived in Johannesburg, South Africa my whole life & I have never seen these caterpillar before. There seem to be loads of them in our garden – every where you look. It is currently the peak of summer here. I have attached a picture of one of them.
Could you please help me identify this & if it is dangerous in anyway to humans, pets or plants? And should they be something we need to try get rid of? If so, is there a way to do this & even a way to rather deter them than killing them – I dont like the idea of having to kill them.
Thanks,
Signature: Kind regards Katie Francis

Dear Katie,
We do not provide extermination advice.  We believe these are Stinging Slug Caterpillars in the family Limacodidae, and though we did not locate an exact match to your individuals, this image from iSpot is quite similar looking.  Careless handling or accidentally brushing up against a Stinging Slug Caterpillar may result in a painful reaction to the spines and the symptoms may last several days.

Letter 2 – Baron Butterfly Caterpillar from India

 

Green feathery caterpillar
January 17, 2010
My father found this in his home garden. It’s feathery and looks really beautiful . Is it rare? We never seen anything like this at least.
SB
Bangalore, South India

Dear SB,
We are unable to provide you with a definitive species identification at the moment, but there is a striking similarity to your caterpillar and the Crowned Slug Caterpillar, Isa textula, from North America.  We can say with confidence that they are in the same family, the Stinging Slug Caterpillars in the family Limacodidae.  Handle with care as they can sting.

Correction thanks to Karl
January 18, 2009
Hi Daniel:
Well, I probably would have put money on this being a Limacodid caterpillar, but I could find nothing
that looked like a good candidate. I now think it is probably a Baron (sometimes Baronet) butterfly in
the genus Euthalia (Nymphalidae: Limenitidinae). One online list of Indian butterflies listed 53 species
in this genus so I don’t think we are likely to nail this one down. The caterpillar photos I did find all
looked very similar, for example the Common Baron (E. aconthea), which is found throughout India
(http://wapedia.mobi/en/Common_Baron). I couldn’t find any reference to a stinging threat, but I
would certainly avoid touching any caterpillar that looks this prickly.  It could all be about camouflage;
feathery spines to break up the outline and a mid-dorsal stripe to mimic the mid-vein of a leaf (check
out the link, above). Regards.
Karl

Letter 3 – Stinging Slug Caterpillar from Costa Rica

 

Bugs in Costa Rica
Location:  Osa Peninsula, Costa Rica
October 6, 2010 5:40 am
Hi Bugman–love the site.
Here is a cool looking caterpillar we saw near Matapalo on the Osa Peninsula in Costa Rica. We did not touch it.
Signature:  Simply Bananas

Dear Simply Bananas,
This positively gorgeous caterpillar is a Stinging Slug Caterpillar in the family Limacodidae, and it looks very similar to the Saddleback Caterpillar, Acharia stimulea,  pictured on BugGuide.  You were wise not to touch it.  The Paul and Bill website indicates it might even be our North American species.

Letter 4 – Large Numbers of Stinging Slug Caterpillars reported in South Africa: Latoia vivida

 

Subject: Stinging Slug Caterpillar
Location: Johannesburg, South Africa
January 20, 2015 12:01 pm
Hi Mr Bugman,
Please could you clarify exactly what these demon spawn are… and more precisely how toxic/dangerous they are?
I was pruning a bush and was stung by 5-6 (out of around 100) of these devil bugs! An extremely painful sting that has left an itchy rash…
Any information is appreciated.
Thank you
Signature: Twice bitten, thrice shy.

Dear Twice bitten, thrice shy,
We just posted several images of identical Stinging Slug Caterpillars that also appeared in large numbers in Johannesburg, but we were only able to identify them to the family level of Limacodidae, but we did not search our own archives at that time.  Back in 2011, Karl identified an image of a Stinging Slug Caterpillar as Latoia vivida,  and he provided us with this link to Photo Camel and this link to Outdoor Photo.  The adult is pictured on African Moths.

Letter 5 – Chinese Junk Caterpillar from Australia

 

Caterpiller identify?
February 16, 2010
The photo attached was taken February 16th 2010, in Frankston (A suburb of Melbourne, Australia). Caterpillar was feeding on a Eucalypt flowering gum tree. When disturbed the spins quickly appeared and left a stinging sensation on the skin. Can you please identify it?
Thanks
Rowan Bravington
Melbourne, Australia

Hi Rowan,
Your caterpillar goes by the colorful name Chinese Junk Caterpillar because, according the the Brisbane Insect website: “of their shape and their way of moving like ship at sea.”  The Chinese Junk Caterpillar, or Mottled Cup Moth, Doratifera vulnerans, is in the family Limacodidae.  The Brisbane Insect website has nice images of various instars as well as the cocoon, which looks like an empty cup once the adult moth has emerged.  The caterpillar is capable of stinging if carelessly handled, and apparently the spines are retractable.  Your image shows the spines extended in the defensive position.  This species was included in the 1913 edition of Webster’s Revised Unabridged Dictionary under the definition for the word “sting” with this entry:  “Sting moth (Zo[“o]l.), an Australian moth (Doratifera vulnerans) whose larva is armed, at each end of the body, with four tubercles bearing powerful stinging organs.”  The sting is reported to be quite painful, similar to nettles and leaving a rash.  The caterpillar is also pictured on the Botanic Gardens Trust website.  In North America, members of the family Limacodidae are known as Slug Moths or Slug Caterpillars, and many of them also possess stinging spines. We next searched the Australian Limacodidae page from an excellent Lepidoptera of Australia website which states:  “In Australia, they are also called ‘Spitfires’, ‘Battleships’ or ‘Warships’. This is because many species of the Caterpillars carry pockets of stinging spines, which are everted when the animal is disturbed, and sting anyone accidentally brushing against a tree leaf on which it is sitting. Their shape has also given them the common name ‘Chinese Junks’. The Caterpillars are inclined to sit by day happily exposed on the leaves of their foodplant, as they have a bright warning pattern or coloration. Their shape, coloration and perhaps their slow progression has led to another of their common names: ‘Bondi Trams’.”

Hi Daniel,
Thanks for your reply and information.
Much appreciated.
Cheers
rowan

Letter 6 – Four Spotted Cup Moth Caterpillar

 

Subject:  Rainbow spiky caterpillar
Geographic location of the bug:  Victoria, Australia
Date: 01/03/2018
Time: 08:50 PM EDT
I was at St Andrews  market around February or June 2017 when I saw a strange rainbow caterpillar on the tree. It had green spikes and was about the size of a fingernail. It looked poisonous because of it’s spikes but I have no idea.
How you want your letter signed:  From Bethany

Dear Bethany,
In North America, we refer to this as a Stinging Slug Caterpillar in the family Limacodidae, and in Australia, the family members are known as Cup Moths.  Based on images posted to the Brisbane Insect site, we are confident this is a Four Spotted Cup Moth Caterpillar, Doratifera quadriguttata.  The Brisbane Insect site states:  “The Four-spotted Cup Moth caterpillar is colourful, with pale green body, pink back with black and white patterns on the top.  There are eight green spikes on the each side, at the front and end there are a pair of red spikes. On the top of thorax section, there are four hidden red spikes, will erect with stinging hairs when disturbed.”  According to Butterfly House:  “Red stinging hairs are protruded from the four at the front on the thorax when the caterpillar is disturbed.” 

Letter 7 – Stinging Slug Caterpillar from Singapoer

 

Subject: Caterpillar
Location: Singapore
February 5, 2017 2:07 am
Hi…my sister got bitten by a bright green caterpillar with less than three dark green stripes and has puffy spikes with four orange dots or something
Signature: any way

could you please help me, her hand is “burning” and she claims it’s really painful

Dear any way,
This is a Stinging Slug Caterpillar in the family Limacodidae, and they do not bite.  The puffy spikes are stinging spines.  We have heard reports that the stings from many members of the family are quite painful.  We do not dispense medical advice.  If you sister is in pain, she should visit the doctor.

Letter 8 – Stinging Slug Caterpillar from North Vietnam

 

Subject:  Spiky Caterpillar
Geographic location of the bug:  North Vietnam
Date: 09/26/2017
Time: 08:41 AM EDT
Today, we found this caterpillar. Rather, it found us. It stung of us in the head, and hurt like hell. The locals assured us, that it wasn’t dangerous, just unpleasant. What can you tell us about that nasty fellow?
How you want your letter signed:  The three adventurers

Dear The three adventurers,
This is a gorgeous image of a Stinging Slug Caterpillar in the family Limacodidae.  We will attempt a species identification.  In the meantime, here is an image from Creative Photography that was also taken in Vietnam, but which is most likely a different species.

Letter 9 – Stinging Slug Caterpillar from South Africa

 

Subject: Yellow caterpillar
Location: Johannesburg south africa
January 13, 2016 1:03 pm
I stood on this and am in considerable discomfort. I’m a bit worried that they are poisonous.
Signature: James

Dear James,
This is a Stinging Slug Caterpillar in the family Limacodidae, and it matches this image on iSpot that is only identified to the family level.  We have several images of this Stinging Slug Caterpillar in our archives and we believe it is Latoia vivida.  According to this Taylor Francis Online article:  “Larvae of the moth Latoia vivida (family Limacodidae) have spiny tubercles which cause sharp pain and subsequent urticaria upon contact with human skin.  This study describes the sting’s clinical consequences and evaluates the effect of various pharmacological modifiers on the clinical response.”  We suggest that you refer to that article and consult a physician if your symptoms persist.

Letter 10 – Stinging Slug Caterpillar from Malaysia

 

Stinging slug caterpillar??
September 28, 2009
Hi,
I live in Malaysia and I found this caterpillar under a leaf in my garden. I’ve checked through you website and the closest one that I can find is the stinging slug caterpillar. Could this be a stinging slug caterpillar? Thanx…
-arina-
Malaysia

Hi arina,
You are correct.  This is a Stinging Slug Caterpillar, but we are uncertain of the exact species.

Update from Karl
Daniel:
It is a stinging slug caterpillar and it looks very much like the Blue-striped nettle grub, Parasa lepida (Limacodidae). If that isn’t it it, it must be something closely related. P. lepida is apparently quite common throughout south and southeast Asia, but occurs from Africa to Papua New Guinea and as far north as Japan. Some or all occurrences outside of south and southeast Asia may be unwanted introductions. They are considered a serious agricultural pest wherever they occur, including on palms, rambutan, mango, banana, rubber and tea. And yes, they can inflict a painful sting if touched. The appearance of the larvae varies somewhat by location and stage of development (the blue stripe appears in the third instar), but Arina’s caterpillar looks very similar to the ones posted at http://www.malaeng.com/blog/tmp/2009/09/limacodid1.jpg and http://www.malaeng.com/webboard/index.php?topic=1199.0.  Regards.
Karl

Letter 11 – Archduke Caterpillar from Thailand, NOT Slug Moth Caterpillar

 

Crowned Caterpillar
Location: Chiang Mai, Thailand
January 6, 2012 4:11 pm
Cant Identify this caterpillar, presumably, related to Crowned Caterpillar and Moth.
Thanks
Signature: Does not matter

Dear Does not matter,
While we could not identify your species, and it is not pictured on the Thai Bugs Caterpillar page, it is our opinion that this is one of the Stinging Slug Caterpillars in the family Limacodidae.  Perhaps one of our readers will have better luck with a species identification.

Correction Courtesy of Karl
January 15, 2011
Hi Daniel and Does not matter:
This appears to be another of those Archduke butterfly caterpillars in the genus Lexias. For comparison, see the previous submission by Steven Gehner that was commented on by myself and Keith Wolfe. I am not sure if it is L. pardalis, L. dirtea, L. pardalis dirteana or something else that is closely related, but it is in there somewhere. Keith Wolfe referred to it as the Black-tipped Archduke (L. dirtea).  Regards.  Karl

Letter 12 – Stinging Slug Caterpillar from India

 

Subject: is this stinging slug bug
Location: kukke subramanya, Karnataka, India
October 11, 2014 12:46 am
dear Mr. Bugman
me and my friends had been to trekking and we happened to come across this particular slug.
i was wondering if you could give me a clear idea as to what it exactly is and if the species has been identified .
we found this bug in Kumara parvata, kukke subramanya, karnataka , India
Signature: Aditya

Dear Aditya,
You are correct that this is a Stinging Slug Caterpillar in the family Limacodidae, but we are not having much luck with a species identification.  Your individual looks similar to, but not exactly like, this Stinging Slug Caterpillar from China on FlickR.  It also looks similar to this Wattle Cup Caterpillar, Calcarifera ordinata , that is pictured on the Brisbane Insect Website.

Letter 13 – Stinging Slug Caterpillar from Guyana

 

Subject: Catapiller Destroyed Palm and stings too
Location: Albion, Guyana, South America
June 28, 2017 11:19 am
This little guy and a few of his friends ate up my small palm tree. Didn’t see them under the leaf and hit them with my arm. Arm swelled up and burned.
I just wondering what it is?
Signature: Troy Kozza

Dear Troy,
This is a Stinging Slug Caterpillar in the family Limacodidae, but we are not certain of the species.  It looks very similar to this image from Master File, but it is only identified to the family level.  Perhaps Cesar Crash who runs Insetologia will recognize it.

Letter 14 – Unknown Blue Caterpillar from Tanzania might be a Stinging Slug Caterpillar

 

unidentified caterpillar
Location: Geita Villiage, Mwanza, Tanzania
February 17, 2011 3:07 am
Hi, my daughter spotted this brightly coloured fellow on our garden path we thought it was litter because of the colour. Its the end of the rainy season in Geita, Mwanza which is in north western Tanzania. He did not move very much although produced large quantities of black gunk when we picked him up and he was only about 3cm long. We have seen a most beautiful large butterfly in the garden with this unusual colouring, is it related?
Signature: Sandra Wronsley

Dear Sandra,
At first glance we thought this might be a Giant Silk Moth Caterpillar in the family Saturniidae, but your statement that is is only 3 centimeters long caused us to second guess that idea.  Our second guess was that this might be a Stinging Slug Caterpillar in the family Limacodidae so we wrote to Bill Oehlke who runs the World’s Greatest Saturniidae Site to get his opinion.  Bill wrote back:  “Daniel, I agree with your assessments, but we could be wrong.”  We are going to post your caterpillar and tag it as unidentified in the hope that someone may be able to provide additional information.  We strongly doubt that this blue caterpillar will metamorphose into the large butterfly you sighted, but that is pure conjecture since there is no photo of the butterfly and the caterpillar is unidentified, though we do believe it is probably a Moth Caterpillar.

Letter 15 – Stinging Slug Caterpillar from the Philippines

 

Subject: Can you identify what type of organism this is?
Location: Philippines, cagayan de oro
April 15, 2017 7:52 pm
I just want to know what type of organism this is. I accidentally touch it and it makes me itch.
Signature: N/A

Dear N/A,
This is a Stinging Slug Caterpillar in the family Limacodidae.  It look similar to this individual posted to Jungle Dragon. 

Letter 16 – Stinging Slug Caterpillars from South Africa

 

Subject:  Green caterpillar
Geographic location of the bug:  South Africa, highveld
Date: 02/19/2019
Time: 09:42 AM EDT
Your letter to the bugman:  These are about an inch long, and are aggressively moving through my garden. May be responsible for some painful skin reactions, but unconfirmed. Any idea what they are, and what they’ll turn into?
How you want your letter signed:  Jon

Dear Jon,
These are Stinging Slug Caterpillars in the family Limocodidae and we have previously identified them as Latoia vivida.  Stinging Slug Caterpillars should be handled with extreme caution as they are capable of delivering a painful sting.

Wow, that was fast. Thank you so much!

Letter 17 – Stinging Slug Caterpillar from South Africa

 

South African stinging caterpillar
Hi,
I’m curious if anyone can identify this South African caterpillar. Found dozens of them happily munching Ligustrum ovalifolium – they’re a very good match to the golden-green leaves. They deliver a really painful sting. About an inch long, some a bit larger.
Adrian

Hi Adrian,
While we have not identified the exact species, we can tell you that this is a Slug Caterpillar in the family Limacodidae.

Letter 18 – Stinging Slug Caterpillar from Thailand

 

Subject: Spiny larva
Location: Thailand, Chiang Mai
March 2, 2015 5:36 am
Found that larva eating a leave in my garden.
No good idea to touch it – seems to have a light poison (acetic acid or so) in his spines.
Any idea what the adult bug would be?
Signature: Regards from the sunny Thailand

We believe this is a Stinging Slug Caterpillar in the family Limacodidae.

Letter 19 – Crowned Slug Caterpillar

 

Flabbergasted
Location:  Capon Springs, West Virginia
September 27, 2010 11:11 pm
I found this bug while on vacation… can you identify it? Is it even a bug? From what I can see, slugs have snails and caterpillars have… this guy. Or maybe it’s a small rodent disguised in fluorescent green armadillo shell? Haha…
This was found on a sidewalk in Capon Springs, WV around 9:30am. It’s about 3/4 inch long and 1/2 in wide. I got him (?) to clasp on to the twig and then he barely moved at all. Thanks for your help!
Signature:  ~Lisa

Hi Lisa,
Your logic about slugs was actually in the right direction.  This is called a Crowned Slug, but it is really a caterpillar, Isa textula.  You were also wise to use a twig while handling the Crowned Slug as it is a stinging caterpillar.  The Crowned Slug is often found feeding on the leaves of oak trees, bug according to BugGuide, they will also feed upon the leaves of “cherry, maple, basswood, elm and beech.“

Letter 20 – Beutenmueller's Slug Moth Caterpillar

 

dainty snowflake worm
August 30, 2009
dear bugman,
what is this? it was on my porch.
bug whisperer
Middle Tennessee

Dear bug whisperer,
BugGuide lists Beutenmueller’s Slug Moth Caterpillar, Isochaetes beutenmuelleri, as uncommon.  It is also known as the Spun Glass Slug Moth and caterpillars feed on swamp oak leaves.  Many of the caterpillars in the Slug Moth Family Limacodidae are capable of stinging, but we are unsure is this species has the stinging spines.  Your photo indicates that it probably does.

Letter 21 – Crowned Slug

 

Maybe a caterpillar?
Location: Tallahassee, fl in the fall
October 13, 2011 12:03 pm
This bug has been crawling on my car for about 3 days. I tried to put it on a leaf and it got all puffed up and wouldn’t come off.
Signature: Jessica

Hi Jessica,
You are correct that this is a caterpillar.  More specifically, it is a Crowned Slug, Isa textula, one of the stinging Slug Caterpillars in the family Limacodidae.

Letter 22 – Crowned Slug

 

Subject: flat green bug
Location: Alstead, NH
October 7, 2013 8:38 am
Hi, this was crawling across the road, very very slowly, in a heavily wooded setting with a lot of hemlock trees, and mixed oak forest type, in Alstead, NH on October 6, 2013. The Black & White photo was altered to highlight the appendages. Those were not feet as far as we could tell. Thanks!
Signature: Curious in Alstead

Dear Curious in Alstead,
This caterpillar is known as a Crowned Slug, Isa textula.  According to BugGuide:  “Larvae are often found on oak, but also eat leaves of many other trees including cherry, maple, basswood, elm and beech.”  This is a stinging caterpillar and it should be handled with caution.

Letter 23 – Crowned Slug Caterpillar

 

what’s this “bug” or instar stage?
February 20, 2010
Came across this centimetre long insect in mid-autumn along a dirt road beside a forested area. It really stood out for such a small creature.
Bonnie
Forks of the Credit River, ON, Canada

Hi Bonnie,
This is a Crowned Slug Caterpillar, Isa textula.  According to BugGuide:  “Larvae are often found on oak, but also eat leaves of many other trees including cherry, maple, basswood, elm and beech.”  This caterpillar should be handled with care as it is capable of stinging.

Letter 24 – Crowned Slug Caterpillar

 

Subject: green bug we found
Location: Jacksonville, FL
September 8, 2013 3:53 pm
Dear Bugman,
My friend found this green bug on the windshield of his car in Jacksonville, Florida this week,( early September). We’re wondering if you know what kind of bug it is?
Thanks so much,
Signature: Curious

Dear Curious,
This is a Crowned Slug Caterpillar, Isa textula.

Letter 25 – Crowned Slug Caterpillar:

 

Subject: pretty picture
Location: Chapel Hill, NC
October 12, 2016 6:30 pm
I am an amateur bug collector & cannot figure out what in the world this one is.
Found it on a leaf on a sidewalk in the autumn (I believe) of 2013. Chapel Hill, North Carolina. Soft, domed body.
The photo was taken with a camera phone through a simple microscope. Ignored the bug for a little bit, noticed it wasn’t on the microscope, & found it working its way up my nearby brass lamp. Placed back outside on the leaf.
Signature: LT

Dear LT,
This is a Crowned Slug Caterpillar, Isa textula, and we verified its identity on BugGuide.  You should exercise caution in handling the Crowned Slug as it is a member of the Stinging Slug Caterpillar family Limacodidae.

Letter 26 – Crowned Slug Caterpillar Stings Woman in Massachusetts!!!

 

Subject:  What’s that bug?
Geographic location of the bug:  Gulfport ms
Date: 06/26/2021
Time: 06:50 PM EDT
Your letter to the bugman:  This bug was in my mother’s house and stung her.  She said it felt like a bee sting.
How you want your letter signed:  S. Rea

Dear S. Rea,
This is a Stinging Slug Caterpillar in the family Limacodidae, more specifically the Crowned Slug, Isa textula, which is pictured on BugGuide.  According to BugGuide:  “Caution! This is a stinging caterpillar. “

Letter 27 – Macadamia Cup Moth Caterpillar from Australia

 

Subject:  Colourful from Australia
Geographic location of the bug:  Sydney
Date: 05/07/2018
Time: 05:31 PM EDT
Your letter to the bugman:  Hi Bugman, a friend of us found this in Sydney and we have no clue what it is. It’s very beautiful.
How you want your letter signed:  Nexus6

Hi,
We’ve solved the mystery :  There is a parent at our school who is an entomologist. It is the caterpillar of the Macadamia Cup Moth ( Mecytha fasciata ). It will turn into a little brown and white furry moth.
Kind regards
Thomas

Dear Thomas,
Thanks for getting back to us.  Of course, though you have provided an identification, we are still posting your image and query because we could not pass up a subject line:  “Colourful from Australia.”  In North America, this family is commonly called the Stinging Slug Caterpillars because many species have venomous spines.  The Macadamia Cup Moth Caterpillar is also pictured on Australian Nature and Dave’s Garden.  According to Butterfly House “This Caterpillar is green with a yellow stripe down its back. Unusually for this family, it has no tubercles, but is smoothly rounded.”  That is an indication this species does not sting.

Letter 28 – Mottled Cup Caterpillar: Australian Stinging Slug Caterpillar

 

Stinging Caterpillar.
Hi Bugman,
whilst walking past a eucalyptus tree whilst on holiday in Queensland, Australia, my ear and side of head just brushed a leaf and I received a stinging sensation. On returning to investigate I found what I believe to be the culprit and have attached a photo. Be interested if this is a common bug.
Regards,
Peter.

Hi Peter,
Your caterpillar bears an uncanny resemblance to a North American species known as the Saddleback Caterpillar, Sibine stimulea, except for the coloration. We suspect it is a close relative, one of the Slug Caterpillars in the family Limacodidae, many of which have stinging spines.

Dear WTB
The Stinging Slug Caterpillar is a Mottled Cup Moth, Doratifera vulnerans, found throughout Australia. They eat the foliage of Eucalypts, Melaleuca and sometimes exotics. The Moth is brown and hairy.
Regards,
Grev

Letter 29 – Nason's Slug

 

I have never seen this before
Location:  Dixon Missouri, USA
August 14, 2010 5:05 pm
this insect stung my son when he swept it off his arm after trying to shake it off and it sticking to him. its very small about the size of a pea. at the biggest.
tim

Hi Tim,
This is one of the Stinging Slug Caterpillars in the family Limacodidae.  We quickly identified it as Nason’s Slug, Natada nasoni, by searching BugGuide.

Letter 30 – Nason's Slug Caterpillar

 

Hi Bugman,
I work for Russell Cave and we try to get pictures of all critters that we see here and make a photo album out of them. I have 2 caterpillars that I can not identify. I have looked at your site and found some similar but no luck. Could you please help. Thank you very much,
Mary

Hi Mary,
Though we don’t receive as many letters in February as we do in the summer, we are a bit behind in responding. Your green caterpillar is a Nason’s Slug Caterpillar, Natada nasoni. Handle with care since Slug Caterpillars have stinging spines. Your other caterpillar appears to be one of the Noctuid Moths, a very large family of moths. We did a cursory search on BugGuide, but properly identifying this caterpillar might take hours, and still prove unsuccessful.

Letter 31 – Painted Cup Moth Caterpillar from Australia

 

Subject: Bug Identification
Location: Central Victoria, Australia
July 24, 2015 7:54 pm
Hi, just curious about what this little guy might be – and I do mean little – I could barely see him with the naked eye. It is maybe 3mm long, and was found on a gum leaf, with what MIGHT have been eggs embedded in the leaf. Or not. Thanks 🙂
Signature: Ann Jeffree

Dear Ann,
This is a Painted Cup Moth Caterpillar, Doratiphora oxleyi, one of the Slug Caterpillars in the family Limacodidae.  Many members of this family have stinging spines and there is a really nice image on FlickR.  You can read more about the Painted Cup Moth Caterpillar on the Butterfly House website where it states:  “Each shield bears four tubercles. Yellow stinging hairs are protruded from these when the Caterpillar is disturbed. These fold into triangular pockets when the Caterpillar is relaxed.  Along the sides of the caterpillar are fleshy spikes, like a skirt. There is also a flap covering the head. The spikes are translucent, and can be reddish or yellowish. The front pair are especially likely to be red. The caterpillars move like slugs because their legs are reduced.  The caterpillars feed on a variety of: Gum Trees.”  Though we have no shortage of family members on our site, your image is a new species for our archives.

Thanks very much for your reply Daniel. I’m pleased to have been able to send
you a new family member for your files. I will look out for a Painted Moth in
the Spring and see if I can add further to your database.

🙂 Ann

Letter 32 – Parasitized Slug Caterpillar

 

Subject: Can you name this bug?
Location: Xalapa, Veracruz, Mexico. Google maps: 19.522574, -96.927901
August 30, 2014 5:09 pm
Hello, I found this bug. It has at least one week living at the same leaf. Here is the raining season. It does not move even when is raining. However it’s alive because when I was taking some photographs it moved a bit. Could you help me to identify this bug?
Signature: J. A. K.

Dear J.A.K.,
This appears to be a Slug Caterpillar in the family Limacodidae, and it has fallen victim to parasitic wasps, most likely in the family Braconidae.  This image from BugGuide depicts a Slug Caterpillar infested with Braconids.

Dear Daniel,
Thank you for your help. It’s a shame I can’t help this small caterpillar, c’est la vie!.
This “bug world” is amazing, I hope I can learn more.
Cheers,
J Ko.

Letter 33 – Possibly Slug Moth Caterpillar from Australia

 

Subject: Green, yellow and blue caterpillar?
Location: West of Merriwa, NSW, Australia.
April 10, 2015 11:31 pm
Hi,
Is this a caterpillar?
It was about 30mm long, sitting on a Lomandra leaf.
It was in a brigalow forest , about 400m altitude.
Signature: lsbth

Dear lsbth,
We believe this is a Slug Moth Caterpillar or Cup Moth Caterpillar in the family Limacodidae, but we have not been able to locate a matching image to substantiate that belief.  This species does not appear to be pictured on the quite comprehensive Butterfly House website.  Perhaps one of our readers will have more luck than we have had.

 

Letter 34 – Rayed Slug Moth from South Africa

 

Subject: identification
Location: Hartbeespoort, South Africa
November 18, 2014 3:27 am
Good day, I saw this one in my garden on 7th november this year. Later it was on the ground, and an hour later gone. I live in North West Province in South Africa.
Signature: Carla

Dear Carla,
Your moth bears a striking resemblance to North and Central American Flannel Moths in the family Megalopygidae, and we believe your moth is also a member of that family, however, we are currently unable to verify that identification on iSpot as the site is currently unavailable.  Perhaps when iSpot solves its technical problems, we can provide you with a species name.

Baie dankie, saw the answer on ispot: Rayed Slug Moth
Groetjes,
Walter & Carla

Thanks for providing that information so that we can correct the posting of this Rayed Slug Moth from the family Limacodidae.  We are linking to the iSpot page that now includes your sighting.

Letter 35 – Slug Caterpillar

 

Obscure green “boat” bug with suction cup “feet”
LOOOVE the site. Have hatched 2 sets of praying mantis, hatched a female Polyphemus moth who attracted TWELVE(1) males and, also hatched a male Cecropia moth earlier in the summer. Just had a 4″ female mantis attract a male and mate; waiting to see when she’ll lay her egg sack…At any rate, I’ve been a critter gal since my youth and am familiar with many of your typical insects. The attached, though, has me completely perplexed and befuddled. What the heck is it??? It was so neat – slightly less than an inch, bright green, shaped somewhat like a boat, and appeared to have a suction-cup type underside (traveled around on my daughter’s index finger for hours). Sort of an armadillo-type of insect in that it had a hard shell on the outside with a softer section underneath..
Kristin

Hi Kristin,
This is a Slug Moth Caterpillar in the family Limacodidae, but we cannot be certain of the genus or species.

Letter 36 – Slug Caterpillar from Brazil

 

Subject: I think it is a slug
Location: -19.779536, -44.444815
January 24, 2013 9:54 am
Can you help me with this one?
Signature: Landon

Dear Landon,
We do not know how to calculate your location, but we are guessing Brazil.  Please confirm.  This is a Slug Moth Caterpillar in the family Limacodidae, and it looks very similar to a North American species, the Monkey Slug, and we suspect it might be in the same genus Phobetron.

Thank you!
Yes I live in Brazil.

Letter 37 – Slug Caterpillar

 

Subject: caterpillar
Location: central Florida (Bushnell)
June 6, 2015 6:00 pm
found this on the ground… fell from tree… Have yet to see one like this! can you tell me what kind it is? It’s only about 2-2.5 cm long. Help! Thanks!
Signature: Stephen Keszey

Dear Stephen,
Congratulations on recognizing this as a caterpillar.  This is a Slug Moth Caterpillar in the family Limacodidae, and after a bit of searching on BugGuide, we identified it as a Skiff Moth Caterpillar, Prolimacodes badia.  According to BugGuide, the Skiff Moth is “Common; sometimes abundant in Florida … larvae feed on leaves of wide variety of trees and shrubs, including birch, blueberry, cherry, chestnut, Hophornbeam (Ostrya virginiana), oak, poplar, Sweetgale (Myrica gale), willow, and others.”  We will be post-dating your submission to go live toward the end of June as we will be away from the office.

Letter 38 – Slug Caterpillar from Brazil: Spider Caterpillar

 

Bright Red Crab-like Bug
Mon, Jan 19, 2009 at 2:21 PM
My brother found this on a house plant. He lives in Brazil. Have any idea what this is and if it’s poisonous?
Clayton Robinson
Belo Horizonte, Brazil

Hi Clayton,
While we cannot tell you the species, we suspect this is a Slug Caterpillar in the family Limacodidae. Your specimen closely resembles the Monkey Slug or Hag Moth Caterpillar which can be viewed on BugGuide. Slug Caterpillars have stinging spines and the sting can be quite painful and stays irritated for several days.

Update:
Daniel:
I think this slug caterpillar may have been posted before (Brazilian Monkey Slug Caterpillar – December 18th, 2007). In a follow-up note, the poster (Luiz) commented that the local name was “Lagarta-Aranha” which translated roughly to “Spider Caterpillar”. That name seems to be applied to a variety of Limacodidae caterpillars in Brazil, but most commonly to Phobetron hipparchia, an extremely variable species that ranges widely throughout the tropical Americas. That’s the same genus as the North American Monkey Slug Caterpillar (P. pithecium)and they do look very similar. Regards.
Karl

Letter 39 – Slug Caterpillar Moth from Philippines

 

Subject:  Some kind of mimic moth
Geographic location of the bug:  Cagayan de Oro City, Philippines
Date: 01/05/2018
Time: 04:08 AM EDT
Hi sir,
Please help me identify this insect. I think it’s a kind of mimic moth but I’m struggling to picture what it’s trying to mimic. Only found this one specimen inside a building.
How you want your letter signed:  LQ

Dear LQ,
Your moth so closely resembles the Oak Slug Caterpillar Moth, Euclea delphinii, that is pictured on BugGuide and we are confident your moth is in the family Limacodidae.  Philippine Lepidoptera has images of some similar looking moths.

HI Daniel,
You’re a legend mate! Thanks for this! I’ve found the species, it’s a Parasa darma.
I’ve released the poor thing now.
Thanks again!
Cheers,
LeoQ

Letter 40 – Slug Caterpillar: Smaller Parasa

 

Fuzzy Slug in Alpharetta GA
I am not sure if this is a slug… He isn’t slimey like most of the slugs posted on your site. Any ideas? He looks more like a sea slug? Thanks!
Daria G.
Alpharetta, GA

Hi Daria,
This is actually a Slug Caterpillar, probably the Smaller Parasa, Parasa chloris. There are a few photos from Georgia on BugGuide. Slug Caterpillars are known for their stinging spines.

Letter 41 – Slug Caterpillar from South Sudan

 

Subject: caterpillar?
Location: South Sudan, Jonglei State
September 23, 2014 11:58 pm
Hello,
I’ve found this bug in the Sudd of South Sudan (Jonglei State) which looks similar to a slug caterpillar.
But below (if I remember well) there were no legs, rather it was smooth like a snail.
Has this animal been identified and named yet?
Gregor Schmidt
Signature: ??

Dear Gregor,
We agree that this looks like a Slug Caterpillar in the family Limacodidae.  We will attempt to provide you with a species name.

December 13, 2014
Hello Daniel,
thanks for your personal answer.
Will you still provide a scientific name?
If the name is a “slug” caterpillar, does that mean that they don’t have legs like reals slugs?
Gregor

Gracious Gregor,
You must have very slow internet access in South Sudan if our response took three months to reach you.  We have not had any luck with a species identification, but our family identification of Limacodidae stands.  Like other caterpillars, Slug Caterpillars have real legs and prolegs.  Though it is a different species, we have a ventral view of a North American Monkey Slug to demonstrate how small the legs on a Slug Moth Caterpillar appear.

Yes,
you are right that internet access is not easy to get in South Sudan, at least in the remote area where I live. I am a German Catholic priest and work in the countryside for most of the year. My location is Old Fangak in Fangak County (Jonglei State) which can be found with Google earth. The picture was taken about 10 km north-east of Old Fangak in August 2012. After that, I never saw the animal again. Unfortunately, I didn’t photograph the belly to see its legs.
Currently, we are in the focus because of the civil war. I live among the rebels and the government may attack us during the dry season.
Thanks for your quick answer. My next internet access will be in January.
Gregor

Letter 42 – Slug Moth Caterpillar

 

unknown green bug
WTB,
I’ve visited your site many times just to look through all of the interesting photos. My dad had me handling all types of insects and reptiles by the time I was a toddler so I don’t have any problems having them around me. I try not to kill any bugs that I find around my house and yard unless they become destructive. This past weekend I was working in my garden under a large oak tree when I came across an unusuall bug that I’ve never seen before. I don’t think it was dead even though it didn’t move once when I picked up the leaf it was on, not even when I gently nudged it with a twig. It was about half an inch long at best guess, didn’t have any spines on it, and the color in the attached picture is accurate. I posted the picture on a garden forum site and some of the guesses posted were Plumbago or Zebra Blue (Leptotes plinius), spiny oak-slug caterpillar (Euclea delphinii), and a mealybug. I looked up all of them on the internet but couldn’t find any pictures that really matched the bug I found. What do you think it might be? Thank you,
Kara Ericson

Hi Kara,
This is a Slug Moth Caterpillar without a common name. It is Isa textula and it does sting.

Letter 43 – Slug Moth Caterpillar

 

Alien bug
alien looking bug my wife and kids found while gathering walnuts off the ground. cant ID it on your bug site. thank you very educating site,
Jim.

Hi Jim,
This amazing insect is a Slug Moth Caterpillar, Isa textula. Handle with care since it has stinging spines.

Letter 44 – Slug Moth Caterpillar

 

Wierd Green Slug/Bug/Caterpillar
Tue, Oct 14, 2008 at 8:58 AM
Hi, my son and I recently found this(bug) on the ground outside our house. I tried to look it up online, but found nothing. It is very small and strange looking. It sticks to your finger on the bottom it looks like small hairs almost velco like. When touched it seems to shrink up a very small amount you have to watch it VERY close or it doesn’t even look like it is moving. We call it our alien bug. We brought it inside and put it into our plant container, about 6 hours later it was gone, or so we thought until we found a small brown ball in the corner. When I poked it, it opened up and the bug was inside. I took pictures of it and by morning it was in a ball again. What is this? I am so curious. What is it going to turn into when it emerges?
Renee
Macomb, Michigan

Hi Renee,
Your caterpillar is one of the Stinging Slug Moth Caterpillars, Isa textula.  The adult moth is brown and relatively nondescript.  You can see images of both the caterpillar and adult moth on BugGuide.

Letter 45 – Slug Moth Caterpillar

 

I have no leads
Mon, Dec 29, 2008 at 8:30 AM
While working at an Outdoor Ed center, my co-teacher and I discovered this awesome creature and kept him in hopes of finding someone on staff to identify it. We found him in the woods on a particularly balmy day. His underside was nearly translucent and had some sort of fuzz around his perimeter, which was highlighted by bright orange spots, which were also along his back. we named him sid.
Lauren
the woods of Maryland’s Eastern Shore

Hi Lauren,
This is a Slug Moth Caterpillar in the family Limacodidae, probably Isa textula.  Many Slug Moth Caterpillars have stinging spines and they should be handled with caution.

Letter 46 – Slug Moth Caterpillar, but which one???

 

Beautiful Caterpillar
Location: North Carolina
September 3, 2011 11:03 am
I found this beautiful white caterpillar last night while looking for Monkey Slug Caterpillars. I looked around on the internet ,with no luck. I hope you can help our family ID. Thanks for the help with the Spun Glass caterpillar. My two sons liked seeing our photo on your great site.
Signature: Rick Thompson

Hi Rick,
Other than to say that we are nearly certain that is is another Slug Moth Caterpillar in the family Limacodidae, we cannot provide anything definitive, but we have a wild theory.  If you had only provide the front view, we would have most likely stated that this was another Spun Glass Caterpillar because the similarity is so striking, however, the lateral view is quite different.  Our wild theory is based on another letter that was submitted and the theory that was developed: “Speculation over there is that, like you said, it’s not a spun glass slug caterpillar, but it may be just part of one. Maybe a bird got one and shook it at the tentacle floated down and still had some reflex action that made it appear alive.”  Your lateral view appears to be a naked Spun Glass Caterpillar that has lost its appendages.  Many Caterpillars change appearance just prior to pupation.  Some change colors and others lose hairs.  Our new theory is that perhaps this is a Spun Glass Caterpillar, Isochaetes beutenmuelleri, and that it is getting ready to metamorphose.  The appendages might have begun falling off the caterpillar.  That certainly lends credibility that the mystery object in that other letter was a shed Spun Glass Caterpillar tentacle or appendage.  We welcome our readerships comments on this theory.

Letter 47 – Spider Caterpillar from Brazil

 

Subject:  Caterpillar
Geographic location of the bug:  Florianópolis – Brazil
Date: 01/05/2018
Time: 01:29 PM EDT
Dear Mr Bugman, what is this big eating my orange tree?
How you want your letter signed:  Carolina G.

Dear Carolina,
Your caterpillar is related to a similar looking North American caterpillar called a Monkey Slug.  We posted a caterpillar from Brazil in the past that we identified as Phobetron hipparchia, and we learned that it is called Lagarta-Aranha locally, which translates to Spider Caterpillar.  Handle with caution.  This caterpillar can sting.

Letter 48 – Spun Glass Slug Moth Caterpillar

 

Beautiful Caterpillar
Location: North Carolina, USA
August 21, 2011 1:44 am
My two sons and I found this beautiful caterpillar last night. We like to find and photograph strange insects at night. I have tried to identify it with no luck. We hope you can help. We would love to see it on your great site. Thanks for any help you can offer.
Signature: Rick Thompson

Hi Rick,
The Spun Glass Slug Moth Caterpillar, Isochaetes beutenmuelleri, also known by the ponderous common name Beutenmueller’s Slug Moth, is listed on BugGuide as being “uncommon” and it is also indicated that it feeds on “swamp oak.”  Many Caterpillars in the Slug Moth family Limacodidae have stinging hairs and spines and they should be handled with extreme caution.

Letter 49 – Spun Glass Slug Moth Caterpillar

 

Subject: strange sea urchin looking creature
Location: lawrencevilla Ga
September 14, 2014 8:38 pm
Hello. I recently found this strange looking creature which looks like something out n of this world! It looks like a sea urchin looking creature in my back yard . It was just sitting on my trashcan. It is a bright green color and about the size of a dime. It is super sticky and would not respond to my touch or a few drops of water being dropped on it. I have been monitoring it all day and it has not moved a bit. Please take a look at the photos.
Signature: Victor S.

Dear Victor,
This amazing looking caterpillar is a Beutenmueller’s Slug Moth Caterpillar, Isochaetes beutenmuelleri, which we quickly identified on BugGuide thanks to an awesome series of images.  BugGuide also indicates another appropriate common name “Spun Glass Slug Moth.”  Many members of the family of Slug Moth Caterpillars are capable of stinging.

Letter 50 – Stinging Slug Caterpillar

 

mystery Autumn caterpillar
Sat, Nov 22, 2008 at 5:57 AM
My children found this guy on their treehouse in October. We have scoured the internet and our caterpillar field guide for his identity. I suspect this is a moth larva.
J, M, and S
Baton Rouge, LA

Dear J,M, and S,
We are happy to hear the children did not suffer a painful sting after handling this Stinging Slug Caterpillar.  Your specimen is in the genus Euclea.  We found a matching image on BugGuide, but it is not identified to the species level.  The Spiny Oak Slug Moth, Euclea delphinii, is the only species identified in the genus, so your specimen is either a closely related species, or a color variation on the Spiny Oak Slug Moth.

Letter 51 – Stinging Slug Caterpillar

 

Aqua/Black Caterpillar
Location: Walhalla, MI
August 25, 2011 11:40 am
I can’t seem to find this little guy on-line anywhere. He is about an inch long and was close to a tree with moss similar in color.
We were camping in Walhalla, MI. That is close to Ludington, MI. It was the 19th of August 2011. Any leads would be fantastic!
Signature: Edelynn

Hi Edelynn,
According to BugGuide, this is a Stinging Slug Caterpillar in the genus Euclea, and it might be a Spiny Oak Slug Caterpillar, Euclea delphinii, a species reported to be quite variable.  Caterpillars in the family Limacodidae often have stinging spines and they should be handled with caution.

Letter 52 – Stinging Slug Caterpillar

 

Subject:  Stinging caterpillar? It’s a beauty!
Geographic location of the bug:  San Antonio, Tx, 90 degree October day.
Date: 10/21/2017
Time: 02:10 AM EDT
Hello wonderful bugmen!
I found this beauty in my front yard, my kids and I enjoyed it without touching it. I try to teach appreciation without disturbing. Not sure of what exactly we were appreciating, though, but after searching through your fb feed thought maybe it shared some similarities to a stinging caterpillar? It was only maybe 1-1.5” long, small little thing, but gorgeous nonetheless. Thank you for all that you do! I love your site and appreciate your work!
How you want your letter signed:  Monica Barrientes

Dear Monica,
We love your philosophy of educating your children to appreciate the wonders of the natural world while exercising caution.  Many otherwise harmless creatures have developed defenses to protect themselves from predators and other threats, and they do not attach unnecessarily, but caution should be exercised when handling them, though one is often better not handling them.  You are correct that this is a Stinging Slug Caterpillar in the family Limacodidae.  Based on this BugGuide image, we are confident it is in the genus Euclea, a group that includes the Spiny Oak Slug, but we cannot identify the species with certainty.  According to BugGuide:  “NOTE: BugGuide photos from the southeastern states previously identified as Spiny Oak-Slug Moth (Euclea delphinii) have been moved to the genus page because we have no information (as of December 2006) on how to distinguish adults or larvae of delphinii from the virtually identical Euclea nanina.”  Three members of the genus are found in Texas.  According to BugGuide:  “E. delphinii: southern Quebec and New Brunswick to Florida, west to Texas and Oklahoma, north to Minnesota.  E. incisa: Arizona east to central Texas.  E. nanina: South Carolina to Florida, west to Texas.”

Letter 53 – Stinging Slug Caterpillar

 

Subject:  Bright happy worm
Geographic location of the bug:  Livermore, KY
Date: 02/20/2020
Time: 06:37 PM EDT
Your letter to the bugman:  This pretty little worm was found on a tractor in the river bottoms of Livermore,KY. It was late summer, around the end of August when it was found. I have never seen a worm like this before and no one I’ve asked can identify it either. I’d love to know what this little guy’s species is!
How you want your letter signed:  Curious worm lady

Dear Curious worm lady,
Your “bright happy worm” is a perfect example of the concept of “look but don’t touch” because it is a Stinging Slug Caterpillar in the family Limacodidae.  We identified it as a Stinging Rose Caterpiller, Parasa indetermina, thanks to this image on BugGuide.

Letter 54 – Stinging Slug Caterpillar from Belize

 

Subject: Belizean coffee caterpillar
Location: Toledo District, Belize
August 14, 2014 7:08 pm
This was climbing on a coffee bush in coastal southern Belize. What is it and what does it turn into? It was only about an inch long.
Signature: Tanya

Dear Tanya,
This is a Stinging Slug Caterpillar in the family Limacodidae.  Many species in this family will deliver a very painful sting that sometimes also produces an allergic reaction if they are carelessly handled or accidentally brushed against.  We have not been successful in locating a matching image, so the best we can do at this time is to provide the family.

Dear Daniel,
Many thanks for this very speedy response.  We have seen quite a number of different stinging caterpillars here over the years, but never this one.  Not only can one be stung by spiny caterpillars, but also by brushing against the cocoons which also have stinging hairs.  No one has had an allergic reaction (thank goodness), but it’s good to be aware that it can happen.
Sincerely,
Tanya

Letter 55 – Stinging Slug Caterpillar from Borneo

 

Subject:  I’m pretty sure it’s in the stinging slug caterpillar family
Location:  Malaysian Borneo
February 6, 2014
Spotted Jan 2014 in Malaysian Borneo.  I’m pretty sure it’s in the stinging slug caterpillar family but would love to know more
Namaste,
Jennifer

Hi Jennifer,
We agree that this is a Stinging Slug Caterpillar in the family Limacodidae.  It is different from the individuals in our archives from Malaysia, and our web search did not turn up any visual matches.  Perhaps we will be able to determine the species in the future.

Letter 56 – Stinging Slug Caterpillar from Borneo

 

Subject: Caterpillar found in Sepilok Borneo
Location: Sepilok Borneo
August 16, 2016 5:05 am
Can you help my little boy find out what this caterpillar will turn into? We found it in Sepilok Borneo yesterday.
Signature: Thanks amy

Dear Amy,
This is a Stinging Slug Caterpillar in the family Limacodidae.  We have not had any luck identifying the species, but the moths are relatively drab and unassuming looking.  Many of the moths are pictured on the Moths of Borneo site.  You should warn your family that carelessly handling the caterpillar may result in a painful sting.   

Thank you so much for your reply.  Fred was thrilled to know the answer.
Amy Crook

Letter 57 – Stinging Slug Caterpillar from Amazonian Peru

 

Peruvian amazon stinging slug caterpillar?
Mon, Feb 2, 2009 at 10:23 PM
I saw this bug in late July, 2008 in Puerto Maldonado, Peru. I’d be interested to know what you think.
JC
Puerto Maldonado, Peru

Hi JC,
What we think is that you are correct.  This is a Stinging Slug Caterpillar in the family Limacodidae.  We also think it is a gorgeous specimen and that it resembles the Saddleback Caterpillar, Acharia stimulea, from North America, and we believe it may be in the same genus.  We will try to do additional research at a later date.

Update:  August 5, 2012
In trying to clean up some unidentified postings from the past, we found a matching photo of this caterpillar on FlickR where it is identified as Lagarta Acharia (fam. Limacodidae).  We found another photo on FlickR with the genus identified as Acharia.  We now believe Lagarta means caterpillar in Portuguese. 

Letter 58 – Stinging Slug Caterpillar from Australia

 

Can you tell me what this is??
Hi there,
Found this caterpillar on our orange tree today. Do you know it? It certainly can sting!! We live in Queensland, Australia.
Many thanks,
Borris

Hi Borris,
We quickly located your Stinging Slug Caterpillar online. Two different scientific names are given: Calcarifera ordinata (Butler, 1886) and Doratiphora colligans. Orange was not listed as a host plant but mimosa, dogwood and rose is.

Letter 59 – Stinging Slug Caterpillar from India

 

Subject:  Request for Bug identification
Geographic location of the bug:  Badlapur ,District- Thane,state- Maharashtra, India
Date: 08/11/2019
Time: 01:48 PM EDT
Your letter to the bugman:  Got sting from same(image Attached) today in my backyards on wrists it was very painful.
Got bump on sting area.
Requesting Information
How you want your letter signed:  Subhash D

Dear Subhash D,
This is a Stinging Slug Caterpillar in the family Limacodidae, and stings are reported to be quite painful.  We have not had any luck finding a close visual match to your caterpillar, but this image from Learn About Butterflies does illustrate the physical family traits generally associated with Stinging Slug Caterpillars.

Letter 60 – Stinging Slug Caterpillar from Japan

 

Catapillar
This creature could be found in Japan pretty much on anything from peach tree to persimmon, even sometimes cherry bloosoms in groups…. and very very poisoness in case the appearance didn’t suggest it(if you touch it, you feel like you have been burned with branding iron). I’d like to know the english name for the beast and what does he turns into??
Kouta Shimazaki
Japan

Hi Kouta,
We haven’t the time to get you an exact species name right now, but we can provide you with some information. Your caterpillar bears a striking resemblance to a North American species known as the Saddleback Caterpillar which is depicted on BugGuide. Saddleback Caterpillars are in the family Limacodidae, the Slug Caterpillar Moths. Many Slug Caterpillars have stinging spines. Perhaps someone will write in with a comment and correctly identify your exact species. It may not have an English name, but if you don’t mind a more general group name, Slug Caterpillar should suffice. Slug Caterpillar Moths are generally brown with subtle markings.  You can also see photos of adult moths from North America on BugGuide.

Letter 61 – Stinging Slug Caterpillar from Malaysia

 

Stinging Slug Caterpillar from Bako
February 5, 2010
Hi Bugman, I saw this gorgeous critter on my trip to Bako National Park. Ploughed the net and some blog labelled it as Euclea delphinii. But when i did a google image search on it the actual spp looks pretty diff. what’s this???
Peiya
Sarawak, Malaysia

Hi Peiya,
The problem with blogs, including our own, is that there is much misinformation.  We agree that this is a Stinging Slug Caterpillar in the family Limacodidae, and we can tell you with certainty that you are correct that it is not the North American species Euclea delphinii.  It is also appears to be different from the Malaysian Parasa lepida or Blue Striped Nettle Grub we posted several months back.  This may take additional research.

Letter 62 – Stinging Slug Caterpillar from Malaysia

 

Subject: Caterpillar
Location: Ulu Yam, Selangor, Malaysia
January 2, 2013 8:03 pm
What is this?
found it at Ulu Yam, Selangor, Malaysia.
shoot at 5 a.m
Signature: Asyraf

Dear Asyraf,
This is a Stinging Slug Caterpillar in the family Limacodidae, but it appears different from this Malaysian Stinging Slug Caterpillar from our archives or this Blue Striped Nettle Grub, also from Malaysia.  While we can provide a family name, we are unable to provide you with a species at this time.

Letter 63 – Stinging Slug Caterpillar from Singapore

 

Neon Green Caterpillar Fri, May 8, 2009 at 5:35 PM
Hi
I found this caterpillar under a leaf in a forested area near my home. I’ve never seen a neon coloured caterpillar like this before. Could this be a stinging slug caterpillar? I’m pondering as I live in Singapore, and so far all the documentation I’ve read about stinging slugs don’t come from this area of the world. Thanks!
Jeremiah
Singapore

Hi Jeremiah,
This is certainly a Stinging Slug Caterpillar in the family Limacodidae .  While we are not certain of the species identification, perhaps one of our readers will write in with an answer.

Letter 64 – Stinging Slug Caterpillar from South Africa

 

stinging slug caterpillar
Location: Potholes, South Africa
December 6, 2011 5:24 am
Hello,
I am form the Netherlands and i was in 2005 in South Africa for an internship. I was at blyde river canyon (potholes)when i saw this specie. I am searching for 6 years now to find out which specie this is. I hope you can help me out?
Greetings,
Hennie

Dear Hennie,
We agree that this is most likely a Stinging Slug Caterpillar, however, some members of the Saturniidae family also have stinging spines.  We will post your photo and we hope our readership might be able to assist in the identification.

Karl provides a possible genus identification
December 6, 2011
Hi Daniel and Hennie:
Excluding the more common and serious pest species, tropical limacodids are always difficult to identify because of the large number of species and a general lack of online information. South Africa, for instance, has at least 117 species for most of which there is very little information to be found. However, I believe this one belongs to the genus Latoia, which includes at least a dozen South African species. Latoia vivida appears to be a very close match and I believe this is probably the correct species, but I cannot be certain. Here is a link to another photo. Coffee is apparently the preferred larval host plant and the species is considered a serious pest on that crop in central and southern Africa. By the way, I think this may be the same species that was posted on WTB by Adrian back in January, 2008. Regards.  Karl

Letter 65 – Stinging Slug Caterpillar from Taiwan

 

Subject: Stung by a caterpillar
Location: Taiwan, east coast
October 7, 2015 6:40 pm
I found this caterpillar on my head this morning when I got stung by it! It felt like a bee sting – not agony, but fairly sore. Tried looking elsewhere online for ID but to no avail.
I hope you can identify it for me!
Thanks
Signature: Dave

Dear Dave,
This is a Stinging Slug Caterpillar or Cup Moth Caterpillar in the family Limacodidae and we found an excellent series of images from China on FlickR including this close match identified as being in the genus Phlossa.

Letter 66 – Stinging Slug Caterpillar from Tanzania

 

Crazy caterpillar
Location: Amani Nature Reserve, Northeast Tanzania
May 18, 2011 3:18 am
I’ve seen 3 or 4 of these guys now, but the only help I’ve gotten on ID is that it is some type of moth. Anybody out there know?
Signature: Phil

Hi Phil,
This is sure a beautiful photograph.  Our money is on a Stinging Slug Caterpillar from the family Limacodidae, but we haven’t the time at the moment to research an accurate species identification.

Letter 67 – Probably Common Baron Caterpillar, NOT Stinging Slug Caterpillar from Thailand

 

Subject: Fern-Looking Green Caterpillar in Thailand
Location: Chon Buri, Thailand
January 30, 2013 7:27 am
Hi there,
It’s Teacher Becky again from Chon Buri, Thailand. This little critter was found on my gate two days ago (you’ll see the padlock to give you a size reference). After posting to my first grade class Facebook page – it seems many Thai people haven’t seen before either. As a community of learners, we’d really like to know so we can do further research in our class. Thank you!
Signature: Teacher Becky

Dear Teacher Becky,
We are happy you came back to us with another question.  Believe it or not, this is a Caterpillar.  More specifically, it is a Stinging Slug Caterpillar in the family Limacodidae.  Some members of this family produce a nasty skin reaction if they are accidentally encountered, so they should be handled with caution, or better yet, not handled at all.  We have not been able to determine a species for you, however, we did locate a matching image on the Photography Thailand Forum which we now believe is incorrect.

Ed. Note:  Because we have been fooled in the past, we are checking with Keith Wolfe if this might be a relative of the Archduke which we posted in the past.  It seems to be a perfect match to the Common Baron Caterpillar,  Euthalia aconthea.  That is supported with the information on the ButterflyCircle Checklist website which states:  “The caterpillar is green with a yellow dorsal stripe. Its unique appearance makes it appear like a walking TV antenna with its branched spines and processes extending way beyond the caterpillar’s body.”

Wow – just so fascinating  And shame on me for forgetting some important details – such as I have a gigantic mango tree in my front yard.
This is a great experience for my little Thai first graders to practice their identification skills.  Thanks for the quick response!

Keith Wolfe confirms Baron identification
Daniel, yes, this immature butterfly is certainly one of Thailand’s many species of Barons (Euthalia).
Best wishes,
Keith

Letter 68 – Stinging Slug Caterpillar from Japan

 

Subject: Fluorescent green caterpillar
Location: Ibaraki, Japan
August 10, 2017 10:15 pm
Hi!
Found this little guy (ca 3cm) wandering the road near my house today and wondering what he is/what he’s going to be. Have found a lot of similar caterpillars online in the stinging slug variety, but none that match him perfectly.
Can you help identify him for me?
Signature: Nina

Dear Nina,
This is a Stinging Slug Caterpillar in the family Limacodidae, and as its name indicates, it is capable of stinging if it is carelessly handled.  We have found matching images on the internet with two different genus names.  This FlickR image is identified as Latoia consocia, and JP Moths identifies it as Parasa consocia.

Letter 69 – Stinging Slug Caterpillar from Limpopo, Africa

 

Subject: Stinging Slug Caterpillar
Location: Limpopo
January 5, 2016 4:35 am
Dear Bugman.
Thanking you in advance for your time herein.
We went away to Rust De Winter the weekend of 2 Jan 2016 and took note of an interesting caterpillar.
We have tried doing research on this caterpillar, so that we can learn more about it, but we can`t seem to find much info of this caterpillar.
Would you be able to assist?
Regards, Vicky
Signature: Doesn`t matter

Dear Vicky,
We wish you had been able to provide higher resolution files of your lovely images as they are quite degraded when enlarged.  These are Stinging Slug Caterpillars in the family Limacodidae.  We did locate a similar looking image on iSpot, but it is only identified to the family level.

Letter 70 – Stinging Slug Caterpillar from Malaysia

 

Subject: ? Stinging slug caterpillar
Location: malaysia
December 8, 2013 1:29 am
Dear Bugman
Is this a stinging slug caterpillar. My son was bitten on it, while cycling past a bush. It produced a stinging sensation and urticaria on his arm. We live in Kuala Lumpur, Malaysia
Signature: Xav and Con

Dear Xav and Con,
We agree with your identification that this is a Stinging Slug Caterpillar in the family Limacodidae.  We located a matching photo on FlickR, but it is only identified to the family level.  Perhaps one of our readers will have better luck with a species identification.

Letter 71 – Stinging Slug Caterpillar on Windshield

 

Subject:  Pita pocket or taco?
Geographic location of the bug:  Rhode Island, USA
Date: 10/22/2021
Time: 09:16 AM EDT
Your letter to the bugman:  I found this pita pocket squirming it’s way along the windshield of my van. Never have I seen anything like it! Please help. I saw it the first part of October I posted several photos to show its movement
How you want your letter signed:  S.Plante

Dear S. Plante,
This is a Stinging Slug Caterpillar in the family Limacodidae.  Alas, the view from underneath, while interesting, is not ideal for species identification.  It might be a Skiff Moth Caterpillar, Prolimacodes badia, which is pictured on BugGuide.

Letter 72 – Stinging Slug Caterpillar from South Africa

 

Subject: Stinging caterpillar
Location: GAUTENG SPUTH AFRICA
January 8, 2017 1:21 am
Hi here is the photo of the caterpillar. Stinging slug?
Signature: Vaughan

Dear Vaughan,
You are correct that this is a Stinging Slug Caterpillar in the family Limacodidae.  This individual on iSpot looks very similar, but alas, it is only identified to the family level.  This individual on iSpot is not identified either.  We then located a posting on iSpot that looks very similar that is identified as Stroter intermissa, but we have not been able to verify that elsewhere on the internet.

Letter 73 – Stinging Slug Caterpillar stings wife in North Carolina

 

Subject: My Wife Says it Stung Her
Location: Raleigh NC, USA
July 31, 2017 3:14 pm
What kind of bug is this? It was sitting on a fence rail and my wife brushed it with her arm. She said it immediately started to tingle and left her with a (very) small welt.
Signature: Neal

Dear Neal,
We believe we have correctly identified your Stinging Slug Caterpillar as Natada nasoni thanks to this BugGuide image.  According to BugGuide:  “Larvae feed on beech, hickory, and hornbeams.”

 

 

Letter 74 – Stinging Slug Caterpillar from Thailand

 

Subject: Maybe in the Euclidae family?
Location: North of Chiang Mai Thailand
August 20, 2017 12:15 am
I found the caterpillar in Northern Thailand about an hour north of Thailand. It stung someone and want to find more out about it like best treatment as well. It is abot 1.5 THB 2 Cm long.
Signature: Eric

Dear Eric,
We were about to disagree with your identification until we learned on Wikipedia (not our favorite site to reference) that Euclidae is synonymous with Limacodidae, the family that contains Stinging Slug Caterpillars.  This does appear to be a Stinging Slug Caterpillar, but we have not been able to locate a matching image online that might lead to a species identification.  We have no medical credentials and we cannot dispense any medical advice, but we would encourage your acquaintance to seek medical treatment if symptoms persist.

Letter 75 – Stinging Slug Caterpillar from Zambia

 

Subject: caterpillar ID
Location: Zambia
February 10, 2015 1:02 pm
Please identify this caterpillar or it may be a slug caterpillar or some kind of saddleback.
Just after rainy season close to Zambezi river at a lodge near Livingstone, Victoria Falls.
Thank you
Signature: Marc

Dear Marc,
We agree that this is a Stinging Slug Caterpillar in the family Limacodidae, and we will attempt to make a species identification.

Dear Daniel,
Thank you for your prompt response. I really appreciate it. The little horns flare when the caterpillar is disturbed. It reminds me of the nudibrancs you see under the water if you scuba dive… brilliant.
Kind regards

And is not the common name of a nudibranc a Sea Slug?

Letter 76 – Giant Scale Insect from Australia, not Cup Moth Caterpillar

 

An Australian Grub?
February 5, 2010
Hello Bugman, it’s funny, just as you identified my Palm Planthopper, I came across another mystery on my walk. It’s about half an inch in length, and looks a bit like a cross between a pillbug anf a colourful grub.
PS. I contacted Dr Fletcher from Orange Agricultural Institute about the Planthopper, and as a consequence he added my photo of it to their website:
“Lovely pictures of Magia subocellata (Family Lophopidae). This species (and one other species of Magia) is native to North Queensland. It was found a couple of years ago in the tropical palm collection at the Royal Botanic Gardens, Sydney and may well have spread to your area from there.”
http://www1.dpi.nsw.gov.au/keys/fulgor/species/magiasub.html
Ridou Ridou
Sydney, Australia

Hi again Ridou Ridou,
We didn’t do quite as well with this submission.  We are nearly certain this is a Caterpillar in the family Limacodidae, which in the U.S. are known as Slug Caterpillars.  Many of them have stinging spines.  The Brisbane Insect website, which has a few species posted, though none resemble your example, indicates they are called Cup Moths because of the shape of their cocoons, and the caterpillars that sting are known as Spitfires, our new favorite insect name.  Your individual is most probably not one of the stinging species.

Eric Eaton Disagrees
Daniel:
I’m thinking the “cup moth caterpillar” from Australia is actually some kind of giant scale insect, but I have no idea which one.  I could also be totally wrong, but I think it is worth checking into.
Eric

Thanks Eric,
WE will research this tomorrow.

Letter 77 – Unusual Red Stinging Slug Caterpillar

 

Subject:  What is it??
Geographic location of the bug:  Shark Valley, Everglades National Park
Date: 12/13/2019
Time: 01:56 PM EDT
Your letter to the bugman:  Hello!
Never seen anything quite like this. It was on a cocoplum leaf.
How you want your letter signed:  Mike

Dear Mike,
This is definitely a Stinging Slug Caterpillar in the family Limacodidae, but we are uncertain of the species.  The red color is quite unusual.  We believe it might be a Crowned Slug Caterpillar, Isa textula, which is pictured on BugGuide, but we cannot locate any images of red individuals.  Sometimes caterpillars change colors right before metamorphosis.

Letter 78 – Yellow Shouldered Slug Moth Caterpillar

 

Subject:  What is this?
Geographic location of the bug:  Gainesville, Missouri
Date: 05/03/2019
Time: 01:03 AM EDT
Your letter to the bugman:  I found this bug September 7, 2017 and have not been able to identify it. Any thoughts?
How you want your letter signed:  Samantha

Dear Samantha,
This is a Yellow Shouldered Slug Moth Caterpillar, and the only image we have in our archive is parasitized.  Here is a BugGuide image for comparison.  According to BugGuide, the moth is known as the Ochre-winged Hag Moth.  Thanks for letting us know that this was a September sighting.

Letter 79 – Yellow Shouldered Slug Moth Caterpillar parasitized by Braconid

 

Green Round Bug
Location: knob noster missouri
December 21, 2010 3:43 pm
This bug was found on a oak leaf in Knob Noster MO in Aug. It had parasitic wasp eggs laid on its back. I think it may be a species of the tomato hornworm. The color is similar but it’s shaped different. It’s almost oval but, flat on the bottom. One end of it had a little bit of a caterpillar body that would come in and out. It was stuck to the leaf. when I got it off and looked at the under belly it had many legs. almost centipede like.
Signature: I’m just interested in the bug. Whatever is easier

Your caterpillar is most likely a Yellow Shouldered Slug Moth Caterpillar, Lithacodes fasciola, and we agree that the parasites are Braconids.  We found a photo on BugGuide of a similar parasite/host relationship.