Sawfly Larvae: Super Pests

Sawfly larvae are one of the biggest pests of the rose plant, pine trees, and many other species of plants like dogwoods, pears, hibiscus, and so on. Let’s understand how to spot and repel them.

If you see a hairless green larva on your plant leaves, you might be forgiven for thinking it will grow into a beautiful butterfly.

Alas, what you have seen is a sawfly larva, and it looks nothing like a butterfly as an adult.

More importantly, you need to act quickly to get rid of these larvae because they can quickly feed on and defoliate your entire plant.

Let’s learn more about these bugs and what damage they can do to your garden or plantation in this blog.

What Are Sawflies?

These bugs are a group of seven thousand or more species, which are all characterized by their saw-shaped ovipositors (the stinger-like organ that their females use to lay eggs in plants).

They vary in length, going from about 3/32nd of an inch to about 25/32nd inches long. Sawflies are not related to butterflies, despite the similarity in their larvae and caterpillars.

These insects are actually from the family of wasps. Sawflies are nectarivores; they love to suck on flowers for their sugary nectar and help spread pollen in the garden.

These bugs are not poisonous or venomous to humans, though their larvae can do significant damage to gardens.

Lifecycle of The Sawfly

The sawfly spends almost its entire life as a larva, living in this shape for months or even years. But when the bug actually comes out of this stage to become an adult, its life expectancy is hardly 7-9 days.

A typical female sawfly lays eggs by using its ovipositors in the soft flesh of plants (however, some sawflies can even give birth by parthenogenesis, a type of cloning). It lays the eggs in pods as a bunch together.

After hatching, the larvae start feeding on the host plant. Their tendency to cluster together means that the poor plant gets defoliated very quickly.

The larvae go through several stages before finally finding a nice spot to pupate. Typically they pupate either in soil or on the bark of trees.

Sawflies are plant-specific: meaning each species of the sawfly is partial towards only one type of plant, which is what it is named after.

But what is common among all sawflies is that their larvae love to munch on plant leaves, and their infestation can be devastating.

After pupating, when the adult sawfly comes out, it feeds mostly on pollen, honeydew, nectar, sap, and other insects.

How To Tell Sawfly Larvae From Caterpillars

Its actually quite hard to tell the difference between these two, but here are some of the things you should look out for:

These bugs have prolegs (fleshy and unsegmented legs) on every part of their body, but caterpillars only have them in the middle and near the tail.

In fact, caterpillars never have more than five of these prolegs, but sawfly larvae can have six or more. Another difference is that these bugs look completely hairless, unlike butterfly caterpillars.

Types of Sawfly

Like we said earlier, sawflies pick a plant and stick with it. Here are some of the commonly found sawflies in the world.

Rose Sawfly Larvae

These bugs have larvae that have a large orange-colored head and a greenish-yellow body. They can quickly eat the softer parts of the rose plant leaves but leave the veins. When sawfly larvae on roses are done, it looks like the skeleton of the leaf is still hanging on to the plant.

Pear sawfly

These larvae feed on sweet fruits such as cherries and pears. They also love ornamental plant leaves such as mountain ash, cotoneaster, and others.

The bugs look like small tadpoles and have a dark greenish color. They look shiny from afar, because they put their own liquid waste on top of their bodies.

Pine sawfly

These larvae have an off-white strip running in the middle of their backs which easily separates them from other caterpillars. They are gray-green colored with black heads. 

As the name suggests, these larvae feed on pine needles. They only eat the top layer of the pines, and the leaves end up looking like straws by the time they are done with them.

Dogwood sawfly

These are slightly difficult to spot because they keep changing their colors as they go along their life stages. They might have a white-colored coating at one point, while later on, they grow into black or yellow-colored bugs.

Hibiscus sawfly

These little bugs have black heads and green bodies. They like eating hibiscus and other plants in the mallow family. These larvae start out at the bottom of the leaves and move upwards, leaving the veins untouched.

Scarlet oak sawfly

The larvae cover themselves with slimy, sticky substances, which lets them hang off leaves to keep predators away. They are greenish-yellow, but their bodies are see-through. 

Mountain ash sawfly

These bugs eat mountain ash plants. They have black dots on each side and are colored green. They start out looking black but keep changing their color to a yellowish hue as they grow older.

Columbine sawfly

Columbine sawflies eat on the columbine plant, leaving almost nothing by the end of their feeding frenzy. They are greenish in color and have dark black heads.

How To Get Rid of Sawflies

In itself, eating leaves off a plant does not permanently damage or injure it, so sawflies aren’t necessarily a big problem. 

However, if you have a new garden with young and tender plants, defoliation can cause them a lot of harm. 

Moreover, these bugs are hard to spot due to their color, and many times you won’t find them out until they have already fed and dropped into the soil, so, at that point, there is no need for spraying insecticides.

If you are looking to get your garden rid of these pests, you might try to do the following:

Pick them off

If you spot them early enough, and they are not too many in number, you can just pick them off your plant one by one. 

But if they have grown bigger and older, it is best not to pick them off at that stage. They might be getting ready to pupate, and your plant would have already lost most of its foliage.

Beneficial Insects

Sawfly larvae have many predators: birds love chomping on them, and so do frogs, ants, lizards, and other pests. Predatory wasps are another set of bugs that can take care of your sawfly larva problem for you.

Soapy Water

Soap water is a time-tested method of removing bugs from plants. Fill a small spray bottle and spray the solution on the affected leaves of the plants. The larvae should come right off and fall to the ground.

Insecticides

If nothing else works, you can try insecticides. It is best to stick to organic ones such as neem oil and horticultural oil. You can also use insecticidal soap to do the trick.

If the infestation does not show any signs of abating, even after trying all of these steps, try to use Pyrethrin. Pyrethrin is a powerful insecticide and should be able to remove the larvae from the leaves permanently.

BT (Bacillus thurningiensis)

A common bacterial solution that works on most pests is BT. Unfortunately, BT does not work with sawfly larvae because these are not caterpillars.

Frequently Asked Questions

How do I get rid of Rose slugs?

One of the best ways to get rid of rose slugs is to spray them with a strong jet of water. If that doesn’t work, try using an insecticidal soap solution on them.

Another chemical that might work is spinosad. Spinosad is a natural insect repellant that works on a variety of bugs. Make sure you apply it on both sides of the leaves.

What insecticide kills sawfly larvae?

Residual pesticides that kill on contact are best for killing sawfly larvae. Some of these include lambda-cyhalothrin, permethrin and bifenthrin

Before you try insecticides on your rose leaves, it is better first to try and remove them using natural ways such as spraying water or insecticidal soap.

How long do sawflies live for?

While the larvae can live for months or even years on end, the adult sawfly can only live for about seven to ten days. 

In some sawfly species, the females can reproduce asexually through a process called parthenogenesis, wherein they simply clone themselves.

Where do rose sawflies come from?

The rose slug is a bug that was originally found in Europe but has moved to other parts of the world as well. It is often seen infesting rose plants in the May to June months.

These larvae are yellowish-green and look very much like caterpillars. We have explained above how to differentiate between them and caterpillars.

Wrap Up

Sawfly larvae are a major pest for rose bushes and other plants. They are hard to detect and appear in large numbers, effectively defoliating an entire plant in a matter of days.

It is important to find and remove these larvae from your garden as early as possible. You can try various methods, such as picking them off, using insecticidal soap, or using beneficial insects to get rid of them. Thank you for reading!

Reader Emails

How big of a pest sawfly larvae are can be judged from the numerous concerned emails we have received from our readers over the years. Read on to know what damage they cause and the measures our readers have taken to protect their favorite plants.

Letter 1 – Unknown Sawfly Larvae really is Birch Sawfly

 

What type of caterpillar is this?
I’m hoping you folks can help me identify the type of caterpillar in the photo I’ve attached. They’re ravaging my white birch tree! That aside, I just want to ensure for the most part that it’s safe for my kids to play around the tree. Thanks,
Christian

Hi Christian,
These are not caterpillars, but Sawfly Larvae. Sawflies are non-stinging relatives of wasps. They will not harm your children, but might defoliate your tree if they are plentiful enough. We tried to identify the species, or even genus, but were unable to do so, despite locating a wonderful website devoted to Sawfly Larvae. We got excited when we read the description of the Birch Sawfly, Arge pectoralis, because the coloration matched, but the images on BugGuide show a very different body shape.

Hi Daniel,
Well, you can get excited again! See the attached image. My picture is out of focus, however the body shape is the same. I noticed that they go into that ‘S’ shape whenever any other bug, or my finger, approached it. Thanks for your help,
Christian

Letter 2 – White Cimbex Sawfly Larva

 

Strange white caterpillar under willow tree…
Hello,
I was standing under our curly willow tree when this strange creamy white caterpillar plopped onto some sticks at the base of the tree. I don’t know whether he just fell off or if a bird dropped him. Anyway, I have not been able to find out what kind of caterpillar it is anywhere! He has the distinct black stripe down his back, and tiny black dots along each side. He is very sensitive to being bothered and will curl up tightly like a cutworm at the slightest touch or bothering. One other strange thing was his head was cream colored too. Could he perhaps be an albino of some species? His skin is very smooth and tough feeling. I gave him some willow leaves but he has not tried to eat any yet. Please help me out here! Thank you!
Charity
P.S We live in Michigan.

Hi Charity,
It looks like a Caterpillar, but it is not a Caterpillar. It is a Cimbex Sawfly larva. Sawflies are non-stinging relatives of wasps. We have seen Cimbex Sawflies in yellow, green and pink, but yours is the first white image. Seems they are available in the colors of after dinner mints.

Letter 3 – Cimbicid Sawfly Larva

 

What kind is it?
Dear What’s that bug,
My son found this caterpillar when we were camping lat week. The park nature guy did not know what kind of caterpillar it was can you help from the pictures attached? thanks in advance,
Effie on behalf of Joshua.

Hi Effie and Joshua,
This is not a caterpillar. It is the larva of a Cimbicid Sawfly in the genus Cimbex. Sawflies are non-stinging relatives of bees and wasps.

Letter 4 – Argid Sawfly Larva is Poison Ivy Sawfly

 

whats this bug??
hello,
I am 14 years old and i live in Ohio. I was in my yard yesterday, and i found about 20 of these purple caterpillars on a plant (i think it might be poison ivy). i searched all over the internet but i could not find out what it is. But, i did find your website. Could you tell me what kind of caterpillar it is?? thank you =]
Brittany

Hi Brittany,
We love the striking and clashing magenta and orange coloration on your Argid Sawfly Larva. It seems we have seen this hip color combination on products sold at Target. Sawflies are not caterpillars. They are non-stinging relatives of wasps. This larva most closely matches a specimen on BugGuide called Arge coccinea that feeds on Sumac. It is possible that the color has changed just prior to pupation, or it might be a different but closely related species.

Update: December 24, 2008
We just received a new photo and letter, and our web searching led us to the identification of the Poison Ivy Sawfly, Arge humeralis. Photos of adults can be seen on BugGuide.

Letter 5 – Sawfly Larvae from Australia

 

sawfly larvae
Dear Bugman,
I thought you might like to see this interesting photo of sawfly larvae (Long Tailed Sawfly?) eating a Spotted Gum leaf from both sides! They were in our backyard on the East Coast of NSW Australia. (Spotted Gum used to be a Eucalypt, but it has been reclassified as Corymbia maculata, which doesn’t sound nearly as interesting).
Grev

Hi again Grev,
Thanks for sending us your humorous Sawfly Larvae image. This social feeding pattern is seen in other Sawflies as well.

Letter 6 – Cimbex Sawfly Larvae

 

What’s this caterpillar?
Can anyone identify these caterpillars for me? Two different colourations of the same caterpillar. Found in southeastern Manitoba, Canada.

Dear Mysterious Writer with bilingual tax information,
We currently have an image of a Cimbex Sawfly Larva on our homepage, and in the past we have received images of both chartreuse and salmon colored individuals, but your photo is the first time both color variations were present in the same photograph. Though they look like caterpillars, they are actually in the order of insects that contains wasps, bees and ants.

Letter 7 – Cimbex Sawfly Larva

 

any idea what kind of caterpillar this is and what it will turn into?
Thanks for any suggestions. Found this walking around in Ogunquit
Wayde

Hi Wayde,
This is not a Caterpillar. It is a Cimbex Sawfly Larva. Cimbex Sawflies belong to the same order as wasps, bees and ants.

Letter 8 – Sawfly Larva

 

Hey, about that bright yellow caterpillar…
Hey,
I ran into another one of the same kind today and I took it back for a picture so, disregard the previous email. But it’s this bright yellow caterpillar, found in the redwood forests of northern california (Humboldt County), and I think it was on an Alder tree. When I put it back, it seemed happy to be back on the trunk. I’ve never seen this before, so please help! I’ve already gone through your pages. Thanks
Katie Schmidt

Hi Katie,
Sawfly Larvae are often confused for caterpillars. This is a Cimbex Sawfly, and they are related to wasps.

Letter 9 – Cimbex Sawfly Larva

 

Found in Labrador
Hello, I found this catepillar on the Trans Labrador Highway east of Labrador City, NL in September 2005. It’s the first time I’ve ever seen one. Could you please tell me what it is? Thanks. Cool web site….
Rick

Hi Rick,
Often mistaken for caterpillars, Sawflies are actually related to wasps. This is from the genus Cimbex.

Letter 10 – Sawfly Larvae

 

Caterpillar identification (hopefuilly!)
Hi!
I was digging around hoping that I could ID these guys. I am in upstate, NY (finger lakes) and this was taken Sept 13, 2005. They were happily munching on some Pignut Hickory leaves until I disturbed them, and then their butts went up in the air. I tried touching them with a stick, and they have an amazingly strong ability to push on the stick and act quite aggressively. I have never seen these before, and am hoping for an ID. Thinking of going back there and gathering a couple to wee what they become. Probably a dull, grey moth.
Thanks!
Mark Wyman

Hi Mark,
Sorry for the delay. This one was tough. These are not caterpillars, but the larva of a wasp relative known as a Sawfly. We actually found it while researching a spider wasp after our caterpillar searching turned up nothing. It appears to be Croesus latitarsus, or something very closely related. We located a link on BugGuide that says they raise their bodies to defend themselves.

Letter 11 – Cimbex Sawfly Larvae

 

Caterpillar?
Can you help me ID this caterpillar found on a trail in the mulch, in southern Ohio?
Kim
Caesar Creek Lake

Hi Kim,
Thanks for the Sawfly larvae photo with, I assume, your fingers for scale. Sawflies are not flies, but members of the Hymenoptera which includes Ants, Bees, Wasps, Ichneumons and many other families. We checked with Eric Eaton, an entomologist who believes it is one of the Cimbex species because of the large size. Cimbex americana is usually listed as our largest American sawfly, and the adult somewhat resembles a bumblebee. There are several color varieties as well. The larvae are described as yellow-green, but with the distinct black stripe down the back. Your photo could be a color variation of Cimbex americana or a closely related species. The caterpillar-like larvae feed on the leaves of a variety of trees. They can spurt a fluid when disturbed. The fullgrown larvae then crawls to the ground, where you found them, and find a place to burrow where they make a brownish cocoon to spend the winter. Thank you for adding to our site with a brand new page. We love getting new species.

Letter 12 – Butternut Woolly Worm

 

Need to know what this is
Photo taken in woods in northern Indiana. August 27, 2008 One inch or a little smaller in length. About ten on one plant. Don’t know what the plant is. Thanks Much,
John Hicks

Hi John,
Though it resembles a caterpillar, this is actually a Sawfly Larva known as a Butternut Woolly Worm, Eriocampa juglandis. According to BugGuide, they: “feed on leaves of Black Walnut (Juglans nigra) and Butternut (Juglans cinerea). Also reported on Carya spp. (Hickory).”

Letter 13 – Elm Argid Sawfly Larvae

 

Caterpillar(?) on elm
I love your site. It’s helped me ID a number of crawly friends around my yard. But now I’ve got one I can’t ID. I live in Northborough, MA and I found these chewing away on a sprouted stump in my yard which I think is some sort of elm; it’s got a lot of greenery, but none over about 6ft up. Most of them are feeding all together on one or two hand-sized leaves at a time, and they’re eating the entire leaf except the central supporting vein, and even some of that too, before moving on to the next. The prolegs appear to almost be vestigial; I saw one of them relocating and it curled its abdomen around the twig more like a monkey’s tail to creep forward on it’s front legs. Can you help me ID them? Thanks!
Karen

Hi Karen,
We are nearly certain these are Elm Argid Sawflies, Arge scapularis, as pictured on BugGuide. At the very least, they are probably in the genus Arge. The larvae of many species look very similar.

Letter 14 – Dogwood Sawfly Larvae

 

Massive damage in Connecticut!!
Hello from Connecticut,
I was out in the garden today and noticed that our dogwood shrub was totally without leaves. A few left over ones were mostly chewed. This poor bush suffered from a drought last year and has now been stripped naked! The culprits were piled all over the last remaining leaves. So now the question is, do I dump them into a bucket of soapy water or are they good for the environment? They were here last year too. I hate to kill anything, but have a number of shrubs they could continue to eat. Thanks so much for your advise!
Tricia

Hi Tricia,
We do not give extermination advice. These are Dogwood Sawfly Larvae in the genus Macremphytus.

Update: 908/16/2008)
Thanks for the information Daniel,
They’ve hit the next dogwood bush as well. Our property is a certified wildlife habitat, so extermination is not my choice by any means. Unfortunately, when one species gets out of control, sometimes I need to step in to back it off some. We only use organic methods for everything so we do as little harm as possible. It’s absolutely amazing how many bees, butterflies and hummingbirds we have around the yard! Again, thanks for the help. We know most birds and plants, but now are working on getting to know the insect population.
Tricia

Letter 15 – Cimbex Sawfly Larva

 

New London, NH USA
Can you tell me what these caterpillars are? I think one is a swallowtail but don’t know the other one. Thank You

Your non-caterpillar is a Cimbex Sawfly Larva.

Letter 16 – Dogwood Sawfly Larvae

 

White powdery caterpillars devouring my dogwood!
The culprits look like bird droppings when curled up in a circle under the leaves. When eating (aggressively) they are 11/2 inch long caterpillars with black and white heads and a powdery coating that stuck to me when I pruned and removed leaves with pests and eggs! I sprayed the shrub and the next day there were more! One caterpillar was gold coloured-before or after the powdery coating?? Please help!
Kathy Ferguson
Goderich, (Southern) Ontario, Canada

Hi Kathy,
These are Dogwood Sawflies, Macremphytus tarsatus (or one of two other closely related species in the genus that are difficult to distinguish from one another), and they are related to wasps, so they are not Caterpillars. Dogwood Sawflies, according to BugGuide, have larvae that: “start out covered with a powdery waxy white coating, which they shed later in the year to become yellow with black cross-stripes or spots on top. “

Letter 17 – Dusky Birch Sawfly Larvae

 

Caterpillers??
Hello,
We’ve have found a couple of caterpillers and can’t seem to come up with ‘what they are’. Hoping you can help us out. The yellow and black ones were found on a really young birch (two feet… the birch not the caterpillers!) Now That would be amazing!! They seemed to be chomping happily away at the leaves, and would strike a tail up and curve it along their backside when alarmed, and would also exhibit this behaviour toward each other, but with more of a whipping action. This guys were about one inch in length and only a few milliimetres around. They seem to be hairless. … Both species were found Aug. 7th, 2008, in Spruce Grove, Alberta (just outside of Edmonton), and in sunny locations. We are wondering if we can relocate them on another more mature tree, if it is a native species, as they have set up house on newly planted trees and we don’t think the wee trees can support their eating habits! I’ve attached photos, and hopefully have included all important details, if not, just contact us! Happily birding,
Michelle & Curtis

Hi Michelle and Curtis,
The “caterpillars” you found on the birch are the Larvae of the Dusky Birch Sawfly, Croesus latitarsus. It is a common error to mistake Sawflies for Caterpillars. Sawflies are related to wasps.

Letter 18 – Sawfly Larva

 

Rose caterpillar 2.jpg, Rose caterpillar 1.jpg
We live in Rush, NY (just south of Rochester, NY – western NY) and found these caterpillars devouring my yellow rose bush leaves. There are black little spots/pellets on the leaves as well. Can you help us identify them and also let us know the best way to get rid of them? We would greatly appreciate your help as we have not seen these before. Thank you!!!!
Jen Davin

Hi Jen,
Though they look like caterpillars, this is actually a Sawfly Larva. Sawflies are nonstinging relatives of wasps. There are several Sawfly families, and we believe your specimen is is the family Argidae. It resembles the Birch Sawfly posted to BugGuide. Many Sawflies are social feeders, and the group often exhibits unusual group behavior, with all group members striking unusual poses and changing position in tandem.

Letter 19 – Sawfly Larva

 

What kind of larvae is this?
Sun, Nov 2, 2008 at 8:58 AM
A group of larvae were found here in Discovery Park, an urban wilderness located within Seattle, Washington. It was raining outside and they were found on the lid to a trash container yesterday, November 1st. We tried to identify them using our insect books, but most don’t have pictures of larvae. Can you help us? We’d like to know what these little guys become. We have taken pictures of them. One picture shows the legs well and the other gives you the relative size to a finger. Note: The images look more yellow than they did in reality. The larvae are very white/cream colored (not yellow) with the black coloring that you notice in the pictures.
Education staff at Discovery Park
Seattle, WA, USA

Dear Education Staff,
The best we can do on this is to tell you it is a Sawfly Larva.  Sawflies are a large group in the order Hymenoptera which contains wasps, bees and ants.  Sawfly larvae are often confused with caterpillars.  BugGuide has numerous submissions of unidentified Sawfly Larvae to browse through, but without a host plant, exact identification of your specimen may be very difficult.  Though adult Sawflies resemble bees or wasps, they do not sting.

Letter 20 – Willow Sawfly Larva

 

Black caterpillar with yellow dots on its sides, and blue/white legs. About 4-5cm in length.
Sat, Nov 15, 2008 at 9:32 AM
Hey there!
I was doing some wetland classification earlier this fall (early September), and I happened to stumble upon this little guy in the afternoon. I found him south of Blackwater, in the Beeverton wetland located one and a half hours west of Peterborough Ontario. He was on a tall shrub located along side of an abandoned railway. He’s solid black with yellow spiracles on both of his sides. He also had blue/white abdominal prolegs and solid black thoratic legs. He’s hairless and quite shiny. Hope the picture helps!
Thanks!
Erin G
Thanks!
Beeverton Wetland (Blackwater)

Hi Erin,
We believe this is a Sawfly Larva, and not a caterpillar. We have searched through countless images on Bugguide and could not find an exact match, but we did find one example that was similar. Sawflies are known for striking the pose exhibited in your photograph when they are threatened or otherwise bothered. We will contact Eric Eaton for a second opinion, and also to see if he can give a quick method of distinguishing between caterpillars and sawflies.

Hi Bugman:
This looks like it could be a Willow Sawfly (Nematus ventralis), or a closely related species.  More photos at: Link1 and Link2 .

KK

Letter 21 – Butternut Woolly Worm

 

Woolly caterpillar ID?
Mon, Nov 17, 2008 at 10:16 PM
Hi, Bugman!
I love your site, and I’ve used it many times to identify creepy and not so creepy crawlers, hoppers and fliers that I’ve found while out photographing the wonders of nature. However, I browsed your caterpillar category all the way back to 2005, and didn’t see one of these. The closest was the ‘Laugher’.
This past September, I noticed something white and fluffy on a tree or bush (sorry! I can’t now remember which). On close inspection, it turned out to be a caterpillar, and there wasn’t just one, but many.
They looked for all the world as though they were covered in cotton wool shag carpeting. I wish I could tell you what sort of bush or tree they were feeding on, but I know as much about horticulture as I do entomology, and that’s not a whole lot. Plus I kinda, sorta forgot to take note.
These pics were taken at ~15:40 on the 7th of September in Southwestern Ontario, in an area with diverse habitats nearby. Lots of woods, open spaces, small marshy spots.
I severely reduced the size of the images to save bandwidth, but they should be large enough to identify the subject. If you do want larger ones, you need only ask!
Thanks in advance!!
Frank
Southwestern Ontario, Canada

Hi Frank,
Though it looks like a caterpillar, the Butternut Woolly Worm, Eriocampa juglandis, is actually a Sawfly Larva. Sawflies are non-stinging relatives of wasps and bees. The Butternut Woolly Worm feeds on the leaves of black walnut, butternut and hickory.

Letter 22 – Sawfly Larvae from Australia: AKA Spitfires

 

Caterpillar (6 legs?), Brown, Spikey, Gum forest, Australia
Sun, May 3, 2009 at 5:07 AM
Hi There, we found this squad of unknown bugs when walking in a Gum (Eucalyptus) forest (Dandenong Ranges National Park) at Fern Tree Gully in Victoria, Australia. They were moving uphill as a unit, flicking their tails up when approached. They were on a gravel path and are about 60mm long. We’d love to know what they were. Thanks!
Nick and Kathryn
Fern Tree Gully, Victoria , Australia

Hi Nick and Kathryn,
Though they look like caterpillars, these are actually the larvae of Sawflies. Sawflies are Hymenopterans, the order that includes ants, bees and wasps. Often Sawfly Larvae feed in groups. We are uncertain of your exact species, and perhaps a reader will provide that answer. We are linking to the Brisbane Insect Sawfly page as well.

Hi Daniel,
Thanks so much for your prompt reply.  We’ll keep checking back in case someone can identify their exact species so we could find what the adult would look like.  In the mean time, once we knew they were sawflies we were able to find other references, and the alternative name of ‘spitfires’.  This site has what looks to be the same/similar species:  http://australian-insects.com/lepidoptera/none/sawfly.html
Thanks again for running the site,
Nick and Kathryn

Letter 23 – Hibiscus Sawfly Larva

 

Mallow/Hibiscus Sawfly Larva
Fri, May 29, 2009 at 6:47 AM
I found these larvae devouring our rose mallows and a few on our Malvaviscus. It’s the first year I’ve seen them. I didn’t see this type of sawfly larva on your site, so I’m sending photos of them and a photo of the damage they do to the leaf. Thanks again for all the hard work that goes into keeping up such a great site.
Tim
Memphis, TN

Hi Tim,
Thanks for sending us your photos of a Hibiscus Sawfly Larva, Atomacera decepta.  We are linking to the BugGuide information page on the species.

Letter 24 – Unknown Sawfly Larvae on Roses in England

 

green three legged arched caterpillar
July 29, 2009
These things are eating my roses and they seem to want to travel in three’s!!
Elizabeth
West Sussex, UK

Hi Elizabeth,
Though they look like caterpillars, these are actually Sawfly Larvae.  Sawfies are non-stinging relatives of wasps.  The posture of your Sawfly Larvae is very consistent with the Argid Sawflies like the Birch Sawfly, Arge pectoralis, pictured on BugGuide. We found one photo of the larva of a Rose Sawfly, Arge rosae that was photographed in Spain, but the coloration is different from your specimens, most notably a yellow head versus the black head on your individuals.  We found photos of three additional Sawflies that feed on roses on the University of Minnesota extension website (Roseslug, Endelomyia aethiops, Bristly roseslug, Cladius difformis and curled rose sawfly, Allantus cinctus) but none of them exactly match your specimens either.  Hopefully you will be content with the general identification of Argid Sawfly.

Letter 25 – Butternut WoollyWorm

 

White cottony caterpillar
August 22, 2009
What is this?? My husband and I found several in our garden. We believe they are feeding on young sumac or lilac trees. We have studied caterpillars and moths/butterflies for some time and have never seen this before. Thank you for any assistance.
Donna Riedinger
New Jersey, USA

Hi Donna,
Though the Butternut WoollyWorm, Eriocampa juglandis, resembles a caterpillar and is often mistaken for a caterpillar, it is really the larva of a Sawfly.  Sawflies are classified with Ants, Bees and Wasps.  According to BugGuide:  “Larvae feed on leaves of Black Walnut (Juglans nigra) and Butternut (Juglans cinerea). Also reported on Carya spp. (Hickory).”  The potential host trees you mention are not listed in any sources we used.  According to the Auburn University website:  “Fully grown larva are densely covered with white, cottony or woolly filamentous flocculence.”

Letter 26 – Goat Moth Larva from India

 

Red-chilli like larva
February 28, 2010
The person who took this photo thinks it is a beetle larva.
Suhas
West Bengal, India

Dear Suhas,
There are not enough anatomical features visible in this photo for us to conclusively categorize this larva.  We don’t believe it is a caterpillar or a beetle grub.  We tend to favor it being a Sawfly Larva.  Sawflies are related to bees and wasps, and many species have larvae that resemble caterpillars.  Perhaps one of our readers will be able to assist in a species identification.

Dear Daniel
Thanks a lot for your prompt reply. I will certainly gather more details from the photographer and send it to you soon.
regards
Suhas

Update:  July 13, 2018
A special thanks to Gustaf Fredell who sent in a comment identifying this as a Goat Moth Larva in the family Cossidae and providing this link to Alamy.

Letter 27 – Birch Sawfly Larvae

 

Connecticut caterpillars
Location:  Tunxis State Forest, Connecticut
September 26, 2010 9:56 pm
We saw three different types of caterpillars today. I guess the first two are tussock moths? I have no idea about the ones in the third picture!
Signature:  Aine

Hi Aine,
Your third image of caterpillars are actually impostors.  They are the larvae of Sawflies, nonstinging relatives of bees and wasps.  By comparing your photo to images posted to BugGuide, we believe they may be Birch Sawfly Larvae, Arge pectoralis.

I tried using the Discover Life caterpillar guide, but couldn’t find anything like them – now I know why! They were devouring a birch leaf, so that sounds pretty definite. Thanks!

Letter 28 – Unknown Sawfly Larvae in Mangrove Swamps

 

Tampa Bay Florida swamp bugs
Location: http://www.stpete.org/boyd/
March 26, 2011 3:18 pm
Hello you wonderful people.
I am hoping you might help with this. They and many others of their kind were mostly in pairs, attached and motionless to the underside of some mangrove or perhaps myrtle bush leaves at Boyd Hill Nature Preserve, St Petersburg, FL 33707 (or close to that zip). I asked one of the guides who said, Hmmm, I don’t know.
Perhaps you could help me and I’ll help them?
Signature: margo rose

Dear Margo Rose,
We are relatively certain that these are the Larvae of Sawflies, but beyond that, we have not had any luck finding a species name.  Sawflies are related to Wasps and Bees, and the larvae of many species resemble caterpillars.  Some species of Sawflies have larvae that gregariously feed in great numbers, often defoliating trees.  You may have better luck than we have had by browsing through the images on BugGuide.  Knowing the host plant for certain should help narrow the search.

Letter 29 – Sawfly Larva

 

Canned larvae
Location: San Antonio, TX
April 4, 2011 1:06 am
Hi Daniel,
This caterpillar(?) was in my rosebush dirt, and at first it looked like a grub, but then I plucked him out and he definitely had caterpillar legs. He was maybe half an inch long and very grubby looking. Anyways, I have no idea what he is. Doesn’t he look as if he’s just popped out of a can?
Thanks!
Signature: Bughugger

Dear Bughugger,
You probably realize that many caterpillars are difficult to properly identify, but we do not believe this is a Caterpillar.  In our opinion, this is a Sawfly Larva, and Sawfly Larvae are often confused with Caterpillars.  Many Sawfly Larvae are difficult to properly identify to the species level, but we did find a very close match on BugGuide, but alas, it is unidentified.

Letter 30 – Scarlet Oak Sawfly Larvae

 

Insect on bur oak
Location: Back yard, south Minneapolis, MN
July 14, 2011 8:31 am
Please help me identify this leaf skeletonizer. The bur oak host is very young, planted last fall. Each larva are approximately 1/4” long. If they will cause harm or stress the tree I will remove, as it is only on one leaf. If not, I prefer to let mother nature handle it on her own. Photo was taken on July 13, 2011, cannot find an image in my IPM book from U of Minnesota.
Signature: Julia V

Hi Julia,
We don’t recognize these creatures, and though they look like young caterpillars, we suspect they are more likely larval Sawflies, nonstinging relatives of wasps.  Alas, we haven’t the time to research this at the moment as we are preparing for a long weekend holiday out of town, but we are posting your letter and photo and tagging it as unidentified.  This is our last posting prior to leaving, other than to inform our readers that we will be out of the office until Monday.  You can try searching Bugguide under Sawflies, though these may be Moth Caterpillars.

Update:
We couldn’t resist the temptation to provide an identification, so we did some searching and we believe these are the larvae of the Scarlet Oak Sawfly, Caliroa quercuscoccineae.  Here is the text from the United States Department of Agriculture Pest Alert website:  “The scarlet oak sawfly, Caliroa quercuscoccineae (Dyar) skeletonizes leaves of scarlet, black, pin, and white oaks in eastern North America. It is also called the oak slug sawfly because of the fact that the larvae are covered with a coat of slime that helps them adhere to foliage.  Larvae feed on the lower surface of the leaves, leaving only a fine network of veins which gives the leaf a transparent appearance. Defoliation starts in the upper crown in early summer and progresses downward. By late summer, heavily infested trees may be completely skeletonized.  Larvae overwinter in cocoons in the litter layer, and adults emerge in the spring. The adults, which resemble  small fly-like insects, are about 6-8 mm long and are black with light yellowish legs. Females lay eggs in rows in the lower leaf surface along the sides of the midribs and larger veins. Eggs hatch within 1-2 weeks, depending on the temperature. Several larvae feed on the same leaf. Full-grown larvae are slug-like, yellowish-green, and about 12 mm long. There may be two to three generations per year.  Microbial diseases and other natural enemies generally keep the sawfly in check. In outbreak years, insecticides may be needed on high-value trees.”  We would advise you to remove the leaf and closely monitor the tree for additional Scarlet Oak Sawfly Larvae.  There are additional images on the Forestry Images website, and the information at the bottom of that page states:  “Forestry Images is a joint project of the Center for Invasive Species and Ecosystem Health, USDA Forest Service and International Society of Arboriculture” which makes us wonder if this is an introduced species, but we cannot confirm that at the moment.

Letter 31 – Elm Sawfly Larvae

 

catapillar
Location: west central Wisconsin (USA)
August 4, 2011 7:33 pm
I have a bunch of these worms on a weeping willow tree, what are they & how do I get rid of them? are they dangerous? I have never seen them here before. There are yellow ones & also Pink ones. they look very similar & I suspect they could be males & females. they appear to be eating the tree leaves. We have had warmer then average temps here this year & lots of rain.
Signature: Thanks for any help

Though they look like caterpillars, these are actually the larvae of Elm Sawflies, Cimbex americana.  Sawflies are related to bees and wasps.  We do not give extermination advice.

Letter 32 – Butternut Woolly Worm

 

Dear Daniel,
…  However, how about checking out the flocked insect I have loaded up today.
Thank you,
Jim Kirkland
University of Illinois
Illinois Forest Resource Center

Hi again Jim,
Thanks for sending us this nice photo of a Butternut Woolly Worm, Eriocampa juglandis, the larva of a Sawfly.

Dear Daniel, Thank you very much for the use of the pic.  Thank you also for the id of the butternut woolly worm found last summer in a Black Walnut plantation near Glendale, Illinois.  Jim

Letter 33 – Sawfly Larva, possibly Cypress Sawfly

 

Need ID
Location: Cornville, AZ
May 6, 2012 11:19 am
Found on an Arizona Cypress and an Italian Cypress, need an ID.
Thanks –
Signature: Lou

Hi Lou,
Though it looks like a caterpillar, this is actually the larva of a Sawfly.  Sawflies are related to bees and wasps, but they do not sting.  When larvae are plentiful, they can defoliate trees and introduced species of Sawflies can be especially problematic.  We did find a matching photo on BugGuide by searching key words like “cypress” and “Arizona” however, the individual is only identified to the family level Tenthredinidae.  We found a reference, but no image, on the Pests of Landscape Trees and Shrubs:  An integrated pest management guide by Steve H. Dreistadt online, and it states:  “Cypress Sawfly Susana cupressi  About one-half dozen Susana species sawflies feed on broad-needled conifers in the western United States.  The most important species in California, primarily in the south, is the cypress sawfly.  Cypress sawfly primarily damages cypress, but reportedly also feeds on arborvitae and juniper.  Adult wasps are black and yellow.  Larvae are grayish green with rows of whitish dots.  The cypress sawfly spends the winter in a cocoon in the soil and has one generation per year.”  Though the description does not mention a red head, the gray green color and white spots seems to fit.  We are unable to locate a photo to verify this online. 

Hi Daniel –
Thanks for the speedy reply, info is appreciated.
Will do some additional research based on what you said and will
forward any new info that I find to you.
Many thanks –
One more pic attached, about 1/2′ long, this is a dead one.
Lou

Hi Daniel –
Took a few more shots, confirmed your ID again.
See attached, note the 6 pairs of Prolegs that do not have ‘hooks’ on them as described here –
6 pairs of Prolegs without hooks clearly visible –
Prolegs: The prolegs are stumpy legs that let the caterpillar climb very well, even up vertical surfaces. Caterpillars usually have five pairs of stumpy prolegs on the abdomen. These prolegs have crochets (small grasping hooks) on them. The last pair of prolegs are called anal prolegs; they are at the very end of a caterpillar’s abdomen (hind region). These prolegs disappear in the adult.
Also note that mine has two eyes caterpillars have 6 simple eyes usually as noted here –
Caterpillars have six pairs of simple eyes (ocelli). Ocelli (also called stemmata) are small, simple eyes that can detect changes in light intensity, but cannot form an image. Ocelli are composed of photoreceptors (light-sensitive cells) and pigments. Ocelli are usually located in two clusters of six eyes on the sides of a larva’s head.
More info here –
Sawfly Larva or Caterpillar?
How to Tell the Difference Between Sawfly Larvae and Caterpillars
By Debbie Hadley, About.com Guide

Thanks for all the additional information Lou.

Found a web site with lots of info, here is a link to a Sawfly Larva pic like the
one we found here.
http://www.ipmimages.org/browse/detail.cfm?imgnum=2121084
Lou

Hi again Lou,
In our opinion, the link you provided to the conifer sawfly Gilpinia frutetorum (Fabricius) is not the species you submitted in your photos.  The host plant is listed as red pine, not cypress.

Update:  May 12, 2012
Hi Daniel –
Found a few more here, pics attached, munching away on an Italian Cypress.
Web searches indicate that it’s a Susana Cupressi, a Cypress Sawfly.  Not much in the way
of images available for ID, hope the ones I send make it easier for someone else to
ID these guys.
We also have five or more species of Pine Sawflies in the area, some look very similar.
They had been absent in the area for many years and started showing up again a few years ago.
BT will not kill them but many insecticides like Sevin will.  Most times the infestation is not wide
spread enough for concern, but one must be watchful.
Luckily we have only found a few as we have 13 Italian Cypress, some Arizona Cypress, and
6 recently planted Spartan Juniper.  Will keep an eye on all of them.
Thanks for your assistance.
Lou Nigro

Hi Lou,
We appreciate the photos that you attached and they will be a great help to our readers.  Of especial significance is that they support our initial tentative identification, but we were unable to locate any images to support that identification.  We do not post photos taken from other websites, and we cannot locate the websites where you found those photos.  Can you please send a link?  We will then post the link.

Hi Daniel –
Think I confused you.  The three pics I sent were shot here this morning.
I found one image of a Susana Cupressi on the Web, I find references to it,
but only one image here –
http://bugguide.net/node/view/393948/bgimage
An exact match to mine found in a county South of here.  They thought is was a caterpillar and did
not identify it as a Sawfly.
There are lots of images of other types of Sawflies, one attached is a Black Headed Pine Sawfly.
Not the same species as mine but almost an exact match except for the head color.  Found at
http://www.ipmimages.org/search/action.cfm?q=sawfly
Lots of confusion on this one, not very well known.  Our local bug expert at the garden center
said he has not seen one around here for years, he was quite surprised to see the live one we
brought him.
Lou

Great.  If they are your photos, we will post them.

Letter 34 – Sawfly Larva and Bee

 

What am I seeing?
Location: Cornville, AZ
May 14, 2012
Hi Daniel –
Another pic attached for you, strange one.
What am I seeing here?
We have 10 Italian Cypress appx. 25 ft. tall here that we found the
Sawfly Larva on.  Did not want to take a chance on losing them so I
sprayed them all with Spinosad to kill the larva very early this morning.
Went back a few hours later to see if any of the larva were dead, collected
a few twigs in a plastic pail.  Some larva were dead, some still alive.  Shot
some pics and ran across the attached image.
Is this a newly hatched Sawfly of some other type of insect?
Thanks –
Lou Nigro

Hi Lou,
We are creating a brand new posting for this image and linking to your original submission.  The other insect looks like a parasitic Hymenopteran, possibly a Chalcid Wasp.  There are some similar looking Chalcids, but they have larger hind legs.  Perhaps it is just the camera angle.  The Chalcid is a Parasitic Hymenoptera.  The female lays eggs within a host, usually the larva of a moth, fly or beetle.  It stands to reason that they might also parasitize Sawfly Larvae.  Most parasitic Hymenopterans are host specific.  It is possible that this Sawfly that is underrepresented on the world wide web has a species specific parasite that preys upon it.  We are going to tag this posting as Food Chain even though much of our response is speculation. 

Eric Eaton identifies the Mining Bee
The “wasp” is a bee in the genus Perdita.  How it got there I have no idea.
Eric

Hi Daniel –
Looks like you are right on, took a few more shots from different angles.
Could be a species specific one as the coloring is a bit different.
Depth of field this close is limited, wish the pic was sharper, will shoot a
few more later.
See attached –
Canon 7D, Tamron 180mm Macro Lens, ISO 100, 1/250 sec, f18 using a Canon flash on
ETTL, manual exposure, handheld.
I’m glad to see that there are wasps in the area, even though I killed some of them,
that are helping me out.  Further spraying will be kept to a minimum.
Wasp measured appx. 2mm in length.
Thanks –
Lou

Hi again Lou,
Since we were wrong about the Wasp and it actually being a Bee, we suspect it was collateral damage from your insecticide.  We are not sure why it was found on the Sawfly.

Letter 35 – Sawfly Larvae from Finland: Croesus septentrionalis

 

Subject: Posing caterpillars
Location: Åland (western Finland)
July 12, 2012 3:21 pm
Came across these feeding caterpillars today. It is a new species to me and that rather odd pose is also a first as far as I am concerned. Each caterpillar is slightly less than an inch long. Any idea what they are?
Signature: Stefan

Hi Stefan,
Though they resemble caterpillars, these are actually the larvae of a Sawfly.  Sawflies are related to Bees and Wasps, but they do not sting.  Many have larvae that look like Caterpillars.  We tried a websearch for species found in Finland and quickly found this photo on PHotographers Direct that was identified as Croesus septentrionalis.  Searching that name, we found a wonderful blog entry on The Big Buzz.  The blogger thought she had this particular Sawfly, but the species she found in UK was eventually identified as the Berberis Sawfly.  She did provide this information:  “I opened my trusty Collins Complete British Insects and started looking. Aha – easy. There was a picture a gang of larvae identical to mine: Croesus septentrionalis. So, that was that.  Except of course that it wasn’t. When I went to bed that night thre was something niggling at the back of my mind. According to the Collins, Croesus septentrionalis, if disturbed, ‘raise their rear ends in unison’. Our larvae didn’t do this.”  Your photo shows these Sawfly Larvae raising their rear ends in unison, a behavior believe to discourage predators.   

Letter 36 – Lesser Willow Sawfly Larvae (we believe) from the UK

 

Subject: what is it?
Location: wirral, UK
August 19, 2012 6:06 pm
just trying to ID this?
Signature: ian

Hi ian,
These are Sawfly Larvae and we found a photo on FlickR that looks identical that identified them as Lesser Willow Sawfly Larvae, Nematus pavidus.  We verified that ID on BioLib as well as on Naturespot UK.

Letter 37 – Spitfires: Sawfly Larvae from Australia

 

Subject: HELP!!!
Location: Western Sydney Australia
September 28, 2012 4:26 pm
Hi Bugman, I found groups of these what appear to be caterpillars that seem to have fallen out of a tree onto a driveway at a group of factories – they seem to be working together to move across the driveway, but I’m concerned for their wellbeing, especially that they may be squished by a car…
Signature: Yo, Dumbo 🙂

Dear Yo, Dumbo,
Though they are often mistaken for caterpillars, these are the larvae of Sawflies, members of the insect order that contains wasps and bees.  In Australia, the larvae of Sawflies in the family Pergidae are commonly called Spitfires.  You can compare your photo to the ones posted on the Brisbane Insect website.

Letter 38 – European Sawfly Larvae

 

Subject: European Sawfly larvae picture
Location: Summerside, PEI
June 27, 2013 10:11 am
Today we discovered that these little caterpillars decided to make a home in our lovely pine tree out front. A colony of around 100 little fellows has spawned into our tree, and we hope our tree can handle these hungry little critters!
Signature: Maria D

Hi Maria,
Thank you for submitting your photo of a European Sawfly Larvae, Neodiprion sertifer, infestation.  Your photo is much clearer than the only other example in our archives.  Readers who want more information on this invasive, exotic species can turn to the Ohio State University Extension or the Penn State Extension websites.  According to BugGuide, the European Sawfly was first reported in North America in 1925.

 

Letter 39 – Dogwood Sawfly Larvae

 

Subject: How to get rid of dogwood sawfly larvae
Location: Georgian Bay, Lake Huron
August 30, 2013 12:13 pm
My dogwood bush/tree won’t last the night. Help! Thank you,
from Georgian Bay, Ontario Canada
photos copyright all rights reserved Karen Walsh
Signature: Desperate

Dear Desperate,
We don’t provide extermination advice.  You can try hand picking the Dogwood Sawfly Larvae, Macremphytus tarsatus, but we don’t believe you need to worry about your dogwood surviving.  Loosing its leaves this season will not weaken your plant, however, you will be deprived of the lovely autumn display of the dogwood’s change to red this year.  Populations of plant feeding insects tend to come in cycles.  You might find some helpful information on the Penn State Woody Ornamental Integrated Pest Management sheet or the IPM of Midwest Landscapes sheet.

Thanks so much for replying. Very  helpful!

 

Letter 40 – Elm Sawfly Larva

 

Subject: orange caterpillar
Location: Seward, AK
September 8, 2013 11:01 pm
Hi! My son found this caterpillar crawling on the ground in front of our porch. We have looked a little bit online, and can’t seem to find what kind of caterpillar it is. Can you help?
Signature: Cdean

Hi Cdean,
This is the larva of an Elm Sawfly, Cimbex americana, and they are frequently mistaken for caterpillars.  Sawflies are actually classified in the order Hymenoptera with bees and wasps, though they do not sting.

Letter 41 – Sawfly Larvae, but which species???

 

Subject: caterpillars taking over vine
Location: Louisiana
April 27, 2014 7:27 pm
I have recently begun renovation on an old industrial lot and have been trying to identify many of the plant species that have taken over. I am a novice, so I’m not even sure what the vine is, my guess is morning glory. upon my visit to the lot today I have observed an abundance of an orange headed caterpillar eating away at it. There are very many of these, but they are isolated to one vine. I would greatly appreciate assistance in identifying them as I have great curiosity about the ecosystem in new Orleans, Louisiana. I have taken this photo today, April 27.
Signature: the curious prancing unicorn

Hi curious prancing unicorn,
These are not caterpillars.  They are the larvae of Sawflies, and your mistake is a common error.  Without knowing the species of plant they were feeding upon, it might be difficult to correctly identify these Sawfly Larvae to the species level, but they do resemble this image of Birch Sawflies from BugGuide, so we believe they are in the family Argidae.  You can browse through the images on BugGuide to see if you can find a good match.

Letter 42 – Steel Blue Sawfly Larvae from Australia are Spitfires

 

Subject: please help me identify this bug.
Location: south australia
August 6, 2014 12:08 am
Hey. I was walking home with my friend today and we walked pasted a shrub or a ungrow tree and there was this black bug on it with white spikes. I’m not sure exactly whether it was a spider or an insect but when I wobbled the branch it kind of moved like an octopus. It almost the end of winter and temperature was about 17-20 degrees celsius if the climate helps. The picture I am showing might not be completely clear or from the best angle so I apologise. Hopefully you can identify this bug. Cheers.
Signature: molly

Dear Molly,
When taking images of bugs, it is best to focus on the subject and not the background.  You mistook this aggregation of larvae for a single creature, when it is actually a grouping.  We could tell the branch was some type of Eucalyptus, so we searched for both caterpillars and sawflies that feed on Eucalyptus, and we quickly located an image of Steel Blue Sawflies on the Australian Native Plants Society site, but sadly, only a common name was provided.  The site states:  “Another chewing pest that can appear in large numbers are steel-blue sawfly larvae. They do most of the damage to a tree’s foliage during the night and in daylight hours they gather into groups around small branches. If they are accessible at these times they can be removed by cutting off the branches where they cluster together.”  Armed with that common name, we next located an image on the Australian Museum site where we learned a genus name Perga and the information that “The Steel-blue Sawfly can sometimes cause extensive damage to trees.”  Our third stop was the Museum Victoria site where the Steel Blue Sawfly was Bug of the Month in July 2012.  There we reinforced the common name Spitfire for a Sawfly Larva and we got the species name Perga dorsalis.

Letter 43 – Possibly Sawfly Larvae from Costa Rica

 

Subject: Caterpillar swarm in Costa Rica
Location: Costa Rica higher elevation
October 31, 2014 9:12 am
These caterpillars(?) appear seasonally in the higher elevations in Costa Rica. (1500m/5000′ MSL). They are 3-4″ long and appear to burrow as a group in the ground (in our yard and surrounding farmlands).
We don’t know what they are (or whether they are a problem?) but they have a marvelous locomotion. They crawl on top of each other for awhile, then they all pause as if catching their breath, then resume. This video was taken on the road outside our house.
What are they and do they benefit or damage the plants and animals?
Signature: Bugged in Costa Rica

Dear Bugged in Costa Rica,
We do not believe these are Caterpillars.  We believe they are Sawfly Larvae, relatives of wasps and bees.  There are Australian Sawfly Larvae known as Spitfires that look similar.

Letter 44 – Elm Sawfly Larva

 

Subject: Caterpillar
Location: Minnesota
August 12, 2015 1:34 pm
Dear bugman,
I found a caterpillar at my lake cabin in Minnesota. I would like to know what kind it is, will it turn in a moth, etc.
Signature: from cassie

Dear Cassie,
We lightened up your lateral view and we conclude this is not a Caterpillar.  There are ten legs visible, three true legs and seven prolegs, and because insects have bilateral symmetry, we can deduce that there are seven pairs of prolegs.  Most caterpillars have five pairs of prolegs, though caterpillars from the Inchworm family Geometridae have but two pairs of prolegs.  This is the larva of a Sawfly, and though it really resembles members of the genus Cimbex, including the Elm Sawfly, we have never seen such coloration that we can recall.  Perhaps one of our readers will recognize this Sawfly.

Ed. Note:  August 15, 2015
We finally located an image of an Elm Sawfly Larva on BugGuide with similar coloration, and it is also from Minnesota.

Letter 45 – Predatory Stink Bug Nymph eats Sawfly Larva

 

Subject: Possible stink bug eating red caterpillar
Location: Livingston County, MI
August 22, 2015 8:26 pm
Found this hanging off a leaf in a meadow behind my house. I think the bug is some sort of stinkbug but I have not been able to find a match online. No idea on the caterpillar type.
Signature: Cheryl E.

Dear Cheryl,
This is a Predatory Stink Bug nymph, probably a Spined Soldier Bug nymph based on this BugGuide image, or possibly a member of the genus Apoecilus based on this BugGuide image, but it is not feeding on a caterpillar.  The prey is a Sawfly larva in the family Argidae, and we have a visual match to Arge coccinea thanks to this BugGuide image.

Letter 46 – Butternut Woolly Worms

 

Subject: caterpiller? with white filaments on Black walnut
Location: SE Pennsylvania
September 7, 2015 4:52 am
Hi
Found these bugs on black walnut leaves, some of which were nibbled on.They looked like feathers from a distance.
Located in SE Pennsylvania, temps warm and humid, no rain recentlyf
Signature: Carol Huff

Dear Carol,
Even though they are feeding on black walnut leaves, the common name for your Sawfly Larvae is Butternut Woolly Worm, Eriocampa juglandis.  Sawflies are non-stinging relatives of bees and wasps.  According to BugGuide:  “larvae peculiar, covered with long threads of wax.”

Thanks! Peculiar little buggers!
Ta
Carol

Letter 47 – Tropical Cactus Moth Caterpillar

 

Subject: RE:
Location: Hernando County, FL
January 5, 2016 8:16 pm
Hi there,
This is just a reiteration of an earlier question you got that I also saw. I live about an hour north of Tampa, FL, and saw the same larvae as the one in this photo:
2014/02/11/orange-larvae-caterpillarf-sawflies/
I thought my photos would be a good complement to the others already provided and may help someone else seeking the ID of this bug. The larva moved quickly, but I did not find what they were feeding on. I found them in the vicinity of our cactus garden, but I found they were more on a piece of driftwood than any of the cacti. I only saw them crawling around at that one specific time and don’t believe I caught sight of any others in our garden after that encounter (but there were plenty during that encounter, crawling around quickly but aimlessly). Unfortunately, I did not get a photo of their prolegs that I can find.
This was in late January of last year (so approximately 1 year ago). I haven’t seen anything this year so far, though!
Thanks, and good luck fighting the good fight!
Signature: Fellow Buglover

Dear Fellow Buglover,
Thanks for providing additional images similar to those from a previous posting.  We believe both examples are Sawfly Larvae, and both look very similar to this BugGuide image identified as being in the genus Arge.  Can you provide any information on the size of the individual?

Update:  August 13, 2018
Carpenter Moth Caterpillar
Because of a new query we just received that we are researching, we now believe both this and an additional posting in our archives are Carpenter Moth larvae in the family Cossidae, but we are uncertain of the species since the larvae do not look like any posted to BugGuide., but they do resemble what has tentatively been identified as the Carpenter Moth Caterpillar Macrocassus toluminus from South Africa.

Update:  Tropical Cactus Borers
Ed. Note:  The following is a comment from Cesar Crash.
Those look like Lepidoptera. Found on a cactus garden, may be the cactus moth: https://www.ipmimages.org/browse/detail.cfm?imgnum=5015058 aka Tropical Cactus Borer https://bugguide.net/node/view/78959/bgpage

Thanks so much Cesar.  The mystery is finally solved.  Here is a nice BugGuide image of the caterpillar.  According to BugGuide:  “Imported to the Caribbean to control prickly pear cacti; arrived in the U.S. naturally or in cargo imported from the Caribbean (Johnson and Stiling 1998). Widely dist. in southern FL, spreading east along the Gulf Coast to New Orleans and north along the Atlantic Coast to SC.”  BugGuide also has this interesting statement:  “The moth has become a pest in se US.   This South American moth was introduced into Australia to control cacti, which are not native to that continent and which were becoming a very serious pest. It was so successful that memorials and monuments to it have been erected by grateful citizens there.”

Letter 48 – Sawfly Larva

 

Subject: Caterpillar
Location: Athens, GA
March 27, 2016 9:46 am
Please help!
This guy fell on the windshield my car (I did not notice) and rode with me some distance. What is it? If I cannot find its host plant soon, I don’t know what I can do for it. I have tried feeding it a variety of plants to no avail. It is super tiny and very hard to get a good picture. I hope these pictures can assist!
Signature: Rachel

Dear Rachel,
Though it resembles a Caterpillar, your insect is actually a Sawfly Larva, a relative of wasps and bees from the order Hymenoptera.  According to About Education:  “Caterpillars are the larvae of butterflies and moths, which belong to the order Lepidoptera. Sawfly larvae look similar to caterpillars, but are an entirely different kind of insect. Sawflies are related to bees and wasps, and belong to the order Hymenoptera. Like caterpillars, sawfly larvae usually feed on plant foliage.  How can you tell the difference between a sawfly larva and a caterpillar? Count the prolegs. Caterpillars may have up to five pairs of abdominal prolegs (see parts of a caterpillar diagram), but never have more than five pairs. Sawfly larvae will have six or more pairs of abdominal prolegs*. …  There are, of course, exceptions to every rule. Caterpillars of the family Megalopygidae, the flannel moths, are unusual in having 7 pairs of prolegs (2 more pairs than any other Lepidopteran larvae). ”  Your individual appears to have at least seven pairs of pro-legs.  Based on this BugGuide image, we believe your individual may be a Raspberry Sawfly, Monophadnoides rubi.  If that is the case, according to BugGuide, you should try feeding it rose leaves if you cannot locate raspberry leaves.

Thank you so much for this information! This is so helpful. I had no idea! Wow.
We tried a blackberry leaf earlier. I will go find some rose leaves.
Thank you! Thank you!
Rachel

Letter 49 – Speckled Green Fruitworm on Willow in Alaska

 

Subject: Caterpillars
Location: Anvik, Alaska
June 24, 2016 3:32 am
Hello im from Alaska and we just noticed all these caterpillars everything eating up all the leaves off of willows and trees.. It’s very on common for these to be around here. There trillions of them everything I mean every where. Please let us know if u know what they are. This spring there were millions of Moths flying around that was very weird and wasn’t common at all.
Signature: Kelly Kruger

Dear Kelly,
Alas, there is not enough detail in your images to tell for certain if these are Caterpillars, or as we suspect, Sawfly Larvae.  According to Insects.About.com:  “Caterpillars are the larvae of butterflies and moths, which belong to the order Lepidoptera. Sawfly larvae look similar to caterpillars, but are an entirely different kind of insect. Sawflies are related to bees and wasps, and belong to the order Hymenoptera. Like caterpillars, sawfly larvae usually feed on plant foliage.  How can you tell the difference between a sawfly larva and a caterpillar? Count the prolegs. Caterpillars may have up to five pairs of abdominal prolegs (see parts of a caterpillar diagram), but never have more than five pairs.  Sawfly larvae will have six or more pairs of abdominal prolegs*. Another notable difference, though it requires a closer look, is that caterpillars have tiny hooks called crochets, on the ends of their prolegs. Sawflies don’t.  Another, less obvious difference between caterpillars and sawfly larvae is the number of eyes.  Caterpillars almost always have 12 stemmata, 6 on each side of the head. Sawfly larvae usually have just a single pair of stemmata.”  In two of your images, the camera is entirely too far away to see individual detail in these larvae.  In the one close-up image, the largest larva is partially out of focus, and the only other larva that can be viewed clearly is half cut off at the top of the frame.  We wish we could count the prolegs, though it really seems to us that there appears to be six pairs, which would make these Sawfly Larvae and not Caterpillars, but again, the image is too blurry at that critical part of the anatomy that we cannot be certain.  Additionally, we can find no images online of either Caterpillars or Sawfly Larvae that have this particular coloration and markings.  The jury is still out on your identification request.  Can you return to the willows and get a higher resolution, sharper image? or can you count the prolegs and get back to us?

Update:  December 3, 2016
Thanks to a new comment, we now know, thanks to DNA analysis, that this is a Speckled Green Fruitworm, Orthosia hibisci, a species of Cutworm that is profiled on BugGuide where hosts plants are listed as:  “decidious trees and shrubs including: apple, crabapple, cherries, plums, poplar, maple, willow and white birch.”  It seems to us that this would be a species eagerly eaten by insectivorous birds, and we can’t help but wonder if bird populations in the area are compromised.

Letter 50 – Sawfly Larva

 

Subject: WTB?!
Location: Denver area (larva)
December 12, 2016 10:37 pm
Hello,
I’m trying to positively identify three insects so their Genus species can be part of the file name which will have the Genus species of the flowering plant, too. (You’ll see.)
…The (I think sawfly) larva is on a pincushion cactus blossom and might be two inches long? This is mid-May along the southern edge of the Denver area (Highland Ranch).
I appreciate your even taking the time to consider these.
Best,
Signature: Mark Bennett

Ed Note:  We requested higher resolution images from Mark, and he complied, supplying this additional information.

Hello Daniel,
Here are the three images in their uncropped state. Note, these uncropped images are artwork to me, not science. As such, they are entered in competition at a gallery and could, with luck and the favor of the judges, be selected for display. And, with more luck and perseverance, become salable prints. THUS, please observe my copyright restrictions — you may use the images on your web site and archive, for educational purposes, but they can not be reproduced or shared or in any method used for commercial purposes by you, What’s That Bug?, or any other entity without my express permission. If these terms are acceptable, and accepted, then we’re good. If not, then please delete the attached file(s).
Thanks. I do hope these help the organization.
Mark Bennett Photography
markbennettphoto.com

December 18, 2016
Hi again Mark,
We are finally getting around to posting what we agree appears to be a sawfly larva.  We will attempt to contact Eric Eaton to see if he agrees.  We will be postdating this submission to go live to our site while we are away from the office on Christmas Day because of the beautiful colors represented in your artful image.

Sounds like fun! It is a beautiful image, if I say so myself, and is my favorite for inclusion in the upcoming gallery show in Fort Collins, Colorado. The theme is “animalia” and I’m hoping that my “animal,” being present but not the apparent, initial, focus of the photo will catch the jurors’ eyes.
Have a happy holiday,
Mark

Eric Eaton Confirms Sawfly Larva identification.
Yes, the other is a sawfly larva.  Great job!
Eric Eaton
author Kaufman Field Guide to Insects of North America
http://bugeric.blogspot.com/

Letter 51 – Sawfly Larva from Australia

 

Subject: Caterpillar???
Location: Melbourne, Victoria (Australia)
March 21, 2017 10:36 pm
Me and my sister found this strange caterpillar thing outside. Lately we’ve been having very rainy and humid weather so I don’t know if that caused it’s appearance?
We’d love to know what it is!
Thanks!
Signature: Bridget

Dear Bridget,
This is a Sawfly Larva and it is very easy to confuse a Sawfly Larva for a Caterpillar, but instead of maturing into a butterfly or moth, it will mature into a non-stinging relative of bees and wasps.  We cannot currently access our main “go to” website for Australian identifications, Brisbane Insects, but this does look like a Longtailed Sawfly larva we have in our archives.

Letter 52 – Long-Tailed Sawfly Larva from Australia

 

Subject: What is this?
Location: Windsor victoria
April 2, 2017 10:02 pm
Dear bug man.
We were at a local park and saw this reddish brown caterpillar type bug with a stinger on the tip of its tail. It only had 6 legs that we could see
We took a photo to try to help us identify it.
My 11year old mitchell is fascinated
Signature: Nicole Hoskin

Dear Nicole,
Though it resembles a Caterpillar, this is actually the larva of a Sawfly.  Sawflies are non-stinging relatives of Wasps and Bees, and adult Sawflies are generally mistaken for Wasps or Flies.  Based on images posted to the Brisbane Insect website, we believe your individual is in the subfamily Pterygophorinae, the Long-Tailed Sawflies.

Letter 53 – Sawfly Larva

 

Subject: Unknown red caterpillar
Location: Southwest Ohio
August 6, 2017 8:08 pm
I found this red caterpillar today in a woods in SW Ohio. Andy idea what it is? I’m outside a lot and have never seen one before.
Signature: Terry

Dear Terry,
Though it looks like a Caterpillar, this is actually a Sawfly larva and it will become a non-stinging adult Sawfly related to bees and wasps.  We believe your Sawfly larva is in the genus Cimbex.

Thank you!  I noticed the link you sent was from Caesar Creek Lake, about 40 miles from here.  I’m a biologist, but insects are not my strength, and I’ve never seen one of these before.

Letter 54 – Sawfly Larva from Alaska

 

Subject:  Hairless and Bumpy, Yellow Caterpillar in Alaska
Geographic location of the bug:  Eagle River/Anchorage AK
Date: 09/15/2017
Time: 04:24 AM EDT
It’s Sept. 16 and fall is in full swing, most days are hanging around 60 degrees. I found this smooth yellow caterpillar while hiking around, and curious what it was! Unfortunately the poor fellow didn’t seem to be alive.
How you want your letter signed:  NuttyMuffins

Dear Nutty Muffins,
Though it resembles a caterpillar, this is actually a Sawfly Larva, probably the Elm Sawfly.  Sawflies are non-stinging relatives of wasps and bees.  We love posting images of Alaskan insects.  The adult Elm Sawfly is quite impressive.

Letter 55 – Sawfly Larva

 

Subject:  Not sure what this is
Geographic location of the bug:  Fishhawk Falls, Oregon
Date: 08/26/2018
Time: 07:42 AM EDT
Your letter to the bugman:  Hi, I’m a photographer.  I spotted this little guy the other day and thought it was some kind of caterpillar but, it doesn’t match anything I’ve seen in the area.  as far as I know Its a larva to some bug .  Thank you for your time.
How you want your letter signed:  FilthyPerfection

Dear FilthyPerfection,
Though it looks like a caterpillar, this is actually a Sawfly larva, and Sawflies are non-stinging relatives of bees and wasps.  Based on this BugGuide image and this BugGuide image, we are confident it is Trichiosoma triangulum.  According to BugGuide:  “Larvae feed on leaves of alders (Alnus), ash (Fraxinus), poplars (Populus), willows (Salix), cherries (Prunus).”

Letter 56 – Sawfly Larva might be Roseslug

 

Subject:  I am trying to care for this little friend and I have no idea what he is..
Geographic location of the bug:  New Hampshire
Date: 06/07/2019
Time: 08:25 PM EDT
Your letter to the bugman:  I thought he was an inchworm but.. when I Google ‘inchworm’, I cant find any like him. Please help, it would be super appreciated!!
How you want your letter signed:  Not sure what this means.. whichever way you’d like, I guess

This is NOT an Inchworm, nor is it another species of Caterpillar.  This is the larva of a Sawfly, a non-stinging relative of Bees and Wasps.  It closely resembles the Roseslug, Endelomyia aethiops, pictured on Ecological Landscape Alliance where it states:  “During the months of May and June in the Northeast you may have noticed leaf discoloration in the form of blotches on your rose leaves (Figure 1). If you inspect the leaves closely you will see the culprit! It is a small, narrow bodied larva called the roseslug sawfly, an introduced pest from Europe. The larvae have pale green colored bodies and light tan-orange colored heads.”  Here is a BugGuide image.  The best way to care for this Sawfly larva is to feed it leaves from the plant upon which it was found.

Letter 57 – Elm Sawfly Larva

 

Subject:  Caterpillar identification request
Geographic location of the bug:  Redmond, WA
Date: 06/28/2019
Time: 06:00 PM EDT
Your letter to the bugman:  Found this on a local street.Any idea what type of caterpillar this is? Thanks!
How you want your letter signed:  Don

Dear Don,
Though it resembles a Caterpillar, the Elm Sawfly larva, Cimbex americana, is actually a member of the insect order that includes Wasps and Bees.

Thank you so much! Really appreciate your knowledge!

Letter 58 – Sawfly Larvae

 

Subject:  Worm found on oak tree
Geographic location of the bug:  Virginia beach, VA
Date: 08/16/2019
Time: 05:05 PM EDT
Your letter to the bugman:  Found these on my oak tree this morning. 8/16/2019
How you want your letter signed:  Thanks, Duane Heidler

Dear Duane,
These are Sawfly larvae.  Sawflies are non-stinging relatives of wasps and bees with larvae that are frequently mistaken for caterpillars.  Based on the appearance of the individuals in this BugGuide image, and that the host plant is oak, we suspect your individuals are in the genus Arge.

Letter 59 – Elm Sawfly Larva with unusual markings

 

Subject:  Unknown Pinkish Caterpillar
Geographic location of the bug:  Motley, MN on a 22acre island on Lake Shamineau
Date: 08/17/2019
Time: 11:06 PM EDT
Your letter to the bugman:  Dear Bugman,
My sons and I were on a Father/Son retreat and we discovered this pinkish caterpillar w/ one long black strip down its back from its head to its rear-end.  It also had several black stripes that ran perpendicular to its one long black stripe.  The total caterpillar length was roughly 1 and 3/4 inch in length.  We know that their are likely many undiscovered insects and maybe caterpillars.  We’re wondering if the caterpillar we discovered on a small tree branch is already identified as we could not find it when searching for caterpillars in MN.  The photo attached is in my Sons terrarium and the red mushroom looking thing next to it is only a decoration.  We didn’t want to touch the caterpillar for a better picture for fear of a sting, or rash.
How you want your letter signed:  Sincerely, Richard Parkos and Sons

Dear Richard,
Thanks for clarifying the identity of that red decoration with the spots.  As we were formatting the image and color correcting it for posting, we obsessed on its identity.  This is not a caterpillar.  We suspected it to be a Sawfly Larva, but the markings are unusual, but our internet search produced several images that confirm our suspicions that this is the larva of an Elm Sawfly.  We have received images in the past of Elm Sawfly larvae that are yellow, green or pink, and they have a black stripe running the length of the body on the dorsal surface, but those traverse stripes are unusual.  There is a small image on the Wisconsin Department of Natural Resources website with a caption that indicates “Elm sawfly larvae are typically yellow; it is uncommon to find the pink form” but it does not mention the traverse stripes.  Additional images on Insects Galore and Forestry Images also document these unusual markings.  The adult Elm Sawfly is a non-stinging relative of wasps and bees.  Elm Sawfly larvae will not sting and they will not produce a rash.

Letter 60 – Dogwood Sawfly larvae

 

Subject:  Caterpillar Identification
Geographic location of the bug:  North Central Pennsylvani
Date: 08/19/2019
Time: 05:44 PM EDT
Your letter to the bugman:  Just want identification of these caterpillars.
How you want your letter signed:  Angelo V

Dear Angelo,
This was a quick identification for us because we encountered an image of Dogwood Sawfly larvae while trying to identify this Introduced Pine Sawfly larva, an identification that took us considerable time. Sawflies are non-stinging relatives of Wasps and Bees that have larvae that are frequently mistaken for caterpillars.  According to BugGuide:  “Young larvae are covered with a powdery white waxy coating. Mature larvae are yellow beneath with black spots or cross-stripes above.”  It is great that your image depicts both waxy coated individuals and those without the coating.

Letter 61 – Elm Sawfly Larva

 

Subject:  Bright Orange Caterpillar
Geographic location of the bug:  Goshen, New Hampshire
Date: 08/23/2019
Time: 09:00 PM EDT
Your letter to the bugman:  Hello! I’ve been trying to figure out what this little guy might be, but I haven’t found anything. It’s bright orange with a single black stripe down the back. The head is white and has many small white dots down the body. I know you don’t respond to all submissions, so thank you if you read mine.
How you want your letter signed:  Haley

Hi Haley,
While this might look like a Caterpillar, it is actually an Elm Sawfly larva. According to the University of Wisconsin Madison Master Gardener Program site, the “Elm Sawfly, Cimbex americana, is a native species which feeds preferentially on elm and willow, but sometimes attacks maple, cottonwood, poplar, birch and other trees. This is one of the largest species of sawfly in North America with full-grown larvae ranging from 1½-2 inches long. The white, light gray, yellow or light green (and occasionally pink) larvae with a rough, pebbly texture have a black stripe running down the top of the body with a row of black dots (spiracles) on each side. They often curl up into a circle when not feeding on the leaves.”