Category Archives: Horntails, Wood Wasps and Sawflies   rss

What's That Bug? does not endorse extermination

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

Hibiscus Sawfly Larva

Hibiscus Sawfly Larva

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.

Hibiscus Sawfly Larva

Hibiscus Sawfly Larva

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

Sawfly Larvae

Sawfly Larvae

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.

Sawfly Larvae

Sawfly Larvae

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

Unknown Sawflies on Coyote Brush

caterpillars in coyote brush (Baccharis pilularis) in Carpinteria, CA
Tue, Mar 31, 2009 at 9:38 PM
I’m not sure what these green caterpillars are. There were hundreds of them in the Coyote Brush (Baccharis pilularis) at the Carpinteria Salt Marsh Nature Park this past weekend.
John Callender
Carpinteria Salt Marsh Nature Park, Carpinteria, CA

Unknown Sawfly on Baccharis

Unknown Sawfly on Baccharis

Hi John,
We will check with Eric Eaton, but we believe these are Sawflies and not Caterpillars. Sawflies are the larval form of a non-stinging member of the order of insects that includes ant, bees and wasps, Hymenoptera.

Update:
Daniel:
Hard to tell from the image, but either sawfly larvae or chrysomelid leaf beetle larvae.
Eric

What's That Bug? does not endorse extermination

Poison Ivy Sawfly

colorful sawfly larva
Tue, Dec 23, 2008 at 10:49 AM
Hi WTB,
I took these photos more than two decades ago in Rhode Island, near an old lime kiln (I was looking for land snails). I always thought this was a caterpillar, but recently when I couldn’t find it in Caterpillars of Eastern North America, I was perplexed. I e-mailed the author of that book, David Wagner, and sent him these photos. He identified it as the poison-ivy-eating sawfly larva. I search the WTB pages and could not find this sawfly larva pictured, so I thought perhaps you would like it.
Keep up the good bug work!
Jeannie
Rhode Island

Poison Ivy Sawfly

Poison Ivy Sawfly

Hi Jeannie,
Long ago we posted an image of an unidentified Sawfly that looked similar. Thanks for sending your photo of a Poison Ivy Sawfly. Out of curiosity, do you have a scientific name?  We did a web search of Poison Ivy Sawfly and found Arge humeralis.  There is a matching image on BugGuide.  We searched our archives for the image we posted in 2007, and sure enough, it was found on Poison Ivy.

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

Butternut Woolly Worm

Butternut Woolly Worm

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.

Butternut Woolly Worm

Butternut Woolly Worm

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)

Sawfly Larva

Sawfly Larva

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

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

Sawfly

Sawfly

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.

Wood Wasp

Big nasty wasp
Thu, Nov 6, 2008 at 3:29 PM
Hi Bugman!
This is a giant crazy wasp that I found in a mist net while banding birds. It was in some coastal scrub habitat in Marin County, California on November 5, 2008. I have no idea what kind of wasp it is.
Walker Pett
Marin County, CA

Wood Wasp

Wood Wasp

Hi Walker,
This is a Wood Wasp or Horntail, and despite its “nasty” appearance, it is perfectly harmless and cannot sting.  We believe this is Urocerus californicus based on images posted to BugGuide.

Pigeon Horntail

Giant winged earwig, maybe?
Since I’ve moved into my house about 5 years ago, every year there has been one or two of there vicious looking bugs on a half dead tree in the middle of my driveway from late spring to late fall. Same looking bug, near the bottom of the tree. The tree is 80% dead, with all the leaves being at the very top.
I never see it eat or fly around. I just sits on the tree and…pulsates. That’s about the best way to describe it. It doesn’t mind the lawnmower. Only ever seen it on the tree. It’s about 4 or 5cm long. I don’t see any holes that it’s living in.
At first I thought it was some sort of wasp because of the way it’s colored, but the more I looked at it, it reminded me of an earwig. One of my friends said, “That’s what wasps looked like when I was young.” Of course, I have the bug identification skills of a cinder block, so that’s why I thought I’d send it to you.
Thanks for any help, it’d be nice to finally put a name to whatever that is.
Thanks
Northwest Ohio

Pigeon Horntail

Pigeon Horntail

Your insect is a Pigeon Horntail, a type of Wood Wasp. This non-stinging species lays eggs in dying and dead trees and the larvae bore into the wood.

Introduced Pine Sawfly

Caterpillar ID please!
Hello Bugman.
Would love it if you could help me id this beauty. I found her in the garden in Chelsea, QC. Isn’t she stunning?
Thanks for your help!
Celine
Québec, Canada
Much appreciated

Introduced Pine Sawfly

Introduced Pine Sawfly

Hi Celine,
This isn’t a caterpillar. It is a Sawfly Larva, a relative of wasps. We believe it is the Introduced Pine Sawfly, Diprion similis. According to BugGuide, the species was “First recorded in Canada in 1931 near Oakville, Ontario, and has not spread naturally much beyond there. There were light infestations in other parts of Ontario in the 1970s and one in southern Quebec in 1940. “

Horntail

is this an ichneumon perhap
My grandson and I found this on a Tamarack tree in the backyard of our home here in southwestern Quebec. He appears to be depositing something in the tree. We would really appreciate your opinion. Thanks
Rory and Billy

Hi Rory and Billy,
This is a Horntail or Wood Wasp. We believe it is Urocerus albicornis according to images posted to BugGuide. The larvae of Horntails are wood boring and they are the primary hosts for the parasitic Giant Ichneumons in the genus Megarhyssa. Your photo is truly stunning.

Elm Sawfly

Caterpillar @ Presque Isle River
Seen: Presque Isle River in MI’s U.P. I did not see this on your site.

You couldn’t locate this “caterpillar” because it is not a caterpillar. It is an Elm Sawfly Larva, Cimbex americana, which can be found on Bugguide.

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).”

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.

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

Pigeon Horntail

Is this an Ichneumon?
I was taking some pics of some Giant Ichneumons ovipositing in a tree and this one was there too. Actually there were 2 of these on the same tree with about 3 Giant Ichneumons. It was just sitting there, but it’s the same size as a Giant Ichneumon but the "butt" is fatter than the others and the ovipositor a whole lot shorter, about a 1/4" long. Thanks!
Francine

Hi Francine,
This is a Pigeon Horntail, Tremex columba, a type of Wood Wasp. This female is depositing eggs that will hatch into wood boring larvae. It is relevant that you found the Pigeon Horntail depositing eggs on the same tree as a Giant Ichneumon because the Megarhyssa species are parasitic on wood boring larva. We found a Colorado State University web page with good information on both species that indicates the Giant Ichneumon is the most common natural enemy of the Pigeon Horntail. The page author, W. Cranshaw, writes of Megarhyssa macrurus: “The adult female can be seen searching the same areas used by the pigeon tremex, although they tend to be present a bit later in the summer. Developing horntail larvae can be detected under the bark by the female and she subsequently drills into the wood to the tunnel of the horntail larva. During egg laying (oviposition) the host larva is paralyzed with a sting after which the egg is laid. The parasitic wasp larva feeds on the paralyzed horntail larva, consuming it completely within a couple of weeks. It then pupates and remains dormant under the bark until the following summer, when the adults emerge. “

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.

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. “

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.

Club-Horned Sawfly from UK

What is this bee like insect with club antennae
Found today Doncaster UK. Is this a bee or a mimic ( has mandibles and unusual club ended antennae) ? Many thanks
Gerry Collins

Hi Gerry,
This is a Club-Horned Sawfly in the family Cimbicidae. Cimbicid Sawflies are related to both bees and wasps, and they do not sting. The larvae look like caterpillars and they are frequently mistaken for them.