Currently viewing the category: "Ichneumons"

Giant Ichneumon
I found this wasp name while searching your web site for pictures to identify a "bug". Now I cannot sleep until I know more about this wasp….if of course I have identified it correctly. You called it a "Giant Ichneumon" in response to an email sent to you by someone else. I think I have one under a glass in my family room….too afraid to move it. I have 3 kids and a dog. This wasp has a black skinny "tail" that is at least 2 inches long and 6 legs that are orange/yellowish and a long skinny body. Did I mention the long antennas? When I look up Ichneumon as a general web search…I don’t get to far with any additional info. What do I do with it and are there many more lurking about? AAaaaghhhh! We live in the pacific northwest. Thanks for any info. I did take pics and will send one on if you need to see it. Thank you in advance,
R. Frances

Dear R. Frances,
Though they are wasps, Giant Ichneumons do not sting. That is an ovipositor for laying eggs deep inside trees where the larvae hunt wood borers. They are beneficial insects for that reason. Try doing a search for the scientific name Megarhyssa atrata for more information.

Photos of Megarhyssa nortoni
Hi Daniel,
Thanks for your quick response….here are 6 lovely photos of the Megarhyssa atrata or Giant Ichneumon. So glad to hear that the tail is not the stinger!! And you will be glad to note my husband released her this morning to the outside. Kinda curious where they are originally found as I have lived in the Seattle area for 30 years and have not seen one here before. Thanks Daniel!
R. Frances

Hi again R. Frances,
After seeing your photos, we can agree they are an Ichneumon of some sort, but the coloring seems a little off for Megarhyssa atrata, though it could be a local variation.
Ed. Note: (09/06/2004) Eric just wrote in identifying this as Megarhyssa nortoni.

I work in Medina Ohio and one of My Marines found this bug and we would like to know what it is?? It is about 4 inchs long thank for any help you can give.
SSgt Horton USMC

Dear SSgt Horton,
Your Marines have captured a female Ichneumon Wasp (Meharhyssa species). That long "stinger" is in fact her ovipositor, and she locates wood boring grubs inside trees with her acute hearing, and penetrates the wood with the ovipositor, depositing an egg near the living grub. The egg hatches and has a living dinner, feasting on the grub until the grub dies from the parasite. We have additional information in our Buggy Biography section as well as on the wasp page of Thank you for the great photo.

I work at a garden store in South-eastern Wisconsin, and recently I caught some type of what I think is a wasp, ITs all black exept for yellow legs, its abdoman is very narrow at first and strechtes into somthing similar to a mud wasp exept it is much bigger. The strangest thing about this insect is it has thrre "tails" or entenas coming directly out of the stinger withc are aproxemiely 5" long. I am stumped, what kind of wasp is this?

Probably a female Ichneumon Wasp, Megarhyssa atrata.

I was outside this morning at about 8:00 am. I live in West Virginia. I happened to look at the corner o my house near where my gas meter is and saw a real strange bug sitting on the wall. It was very dark blue or black had a body that was about 1.5 to 2 inshes long ( approx) . Had wings that were about an 1.5 or so. Had a curved body. It also had this stinger or something ( not sure what to call it. That was about 1/32 inch in diameter and about 5 or 6 inches long. I watched it for a minutes and it flew off. It was so large that i could see it 50 feet away in the air. Do you have any idea on what it was or where i can find information on flying insects? any help will be great.
Big Bad Bob

Dear Bob,
Let me commend you on your excellent verbal description. I believe it is a female Ichneumon Wasp, probably Megarhyssa atrata. She uses that long ovipositor to deposit her eggs deep into wood where the young search out and devour wood eating grubs. Very specialized development that would interest all Darwinians.

Dear Bugman:
I live in the San Francisco Bay area of Northern California, and for the last week or two we have had a new kind of bug flying in large numbers around our house. I’ve included some pictures of them so that you know what they look like (I apologize if the size of the e-mail causes any problems for you.) At first we thought they were just mosquito hawks, but on further examination they are much uglier. They are nocturnal and attracted to light, and we have perhaps a dozen a night or more swarming around our outside lights, and usually a few that get inside the house. They are about an inch to an inch and a half in length, and are one of the more disturbing bugs I’ve seen. They don’t seem to match up with any of the pictures I found of termites or flying ants, but I really want to know if they are since that would be a big problem for the house! At about the same time these bugs appeared, there also have cropped up a couple of spots on the lawn where the dirt looks almost bubbly – I have no idea if that’s related, but I thought it may be some kind of nest. Please let me know what kind of bug this is so I can stop worrying or get rid of them, whichever is appropriate.
Thank you very much.

Dear Helga,
Seldom do we get such a concise description accompanied by such wonderful documentation. There is no speculation regarding my identification. You have a species of Ichneumon wasp, Family Ichneumonidae. These are small solitary wasps which have smaller and slenderer bodies and legs than social and semi-social types. The abdomen is compressed from side to side. Some species are as small as gnats, and the larger ones are up to an inch in length. The specimen you photographed belongs to the genus Ophion. All Ichneumons are parasitic on other insects, and many feed on caterpillars. According to Hogue, "The eggs are inserted into the body of the host by means of the females short sharp ovipositor (which incidentally can penetrate human skin). The larvae feed on the internal tissues and, when mature, pupate within the host." They are important biological controls for many agricultural pests. Your possible nest is obviously something else. The adults are often attracted to lights at night.

Thank you very much. Now I can stop worrying. 🙂