Currently viewing the category: "Parasitic Hymenopterans"
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Subject: Please can you tell me what this is?
Location: Dalby forest. England
August 13, 2016 8:50 am
Saw this in the summer in north east England in a dense forest.
Signature: Perplexed

Sabre Wasp

Sabre Wasp

Dear Perplexed,
This is a parasitoid Ichneumon, the Sabre Wasp,
Rhyssa persuasoria, in the act of ovipositing, and you can verify our identification on Bio Images.  According to Bug Life:  “Wood drillers Ichneumons often locate their host species by ‘smelling’ them and this is exactly what Sabre Wasps do. Female Sabre Wasps locate the wood-boring larvae of the huge and beautiful Horntail Wasp (Uroceris gigas) by using their antennae to detect scents that emanate from the larvae’s wooden tunnels.  When a female Sabre Wasp has located a promising site, she starts tapping on the surface of the wood with her antennae. She then uses her long egg-laying tail to drill a ‘probe’ hole. She may drill a few probe holes before deciding on an appropriate position, and then drills as deep as she can. After 30-60 minutes, if successful, she will breach the tunnel wall, sting the larvae and then lay an egg on its body. With the larvae paralysed by the sting, it awaits the inevitable demise of being consumed alive by the Sabre Wasp grub.”  Your image is gorgeous, and though we have many similar looking images of North American relatives called Stump Stabbers in the act of ovipositing, your image is the first European example we have of your Sabre Wasp in the act of laying eggs.

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Subject: parasitoid wasp
Location: Cochise County, AZ
August 1, 2016 10:15 am
Hello! The bug in the picture seems like a parasitoid wasp and I wonder what kind it is and what it is doing on the cadaver of a rat. It looks like it’s stinging the rat but it shouldn’t be laying eggs on it, right? Maybe feeding on small flies on it? The photo was taken March 8th, 2015. Thank you for your help!
Signature: Kana

Parasitoid Wasp on Rat Carcass

Parasitoid Wasp on Rat Carcass

Dear Kana,
We are currently going back through requests sent in the past few weeks that we did not yet open, and we are awestruck at this image.  We agree it is a Parasitoid Wasp and that the host is likely the immature stage of a fly or beetle that is attracted to carrion.  We have not begun the research on this yet, but we did send your image to Eric Eaton to get his input as well.  We are posting it as unidentified and are going to immediately begin to do some research.  This is a very exciting posting for us and we hope to be able to identify the genus or species for you.  This is the kind of posting that validates our practice of going back a few weeks out of guilt to look at all the requests we have left unanswered.

Parasitoid Wasp on Rat Carcass

Parasitoid Wasp on Rat Carcass

Upon doing a web search for “Braconid on Carrion” we found a Google Books online pdf from The Entomologist’s Monthly Magazine, Volume 43 that states:  “Few Hymenoptera are found in carrion; the commonest is a Braconid, Alysia manducator, which is parasitic upon both the Dipterous and Coleopterous larvae (cf. Marshall, Bracon, d’Europ., ii.377); I first took it on a foal at Brockenhurst in May and subsequently on a rabbit in June, also on a horse’s shin bone and a cow’s head in the same month.  An Ichneumonid, Atractodes bicolor, which may be hyperparasitic on the last species (cf. Morley, Ichn. Brit., i, 291 et ii) was taken in a rabbit in September, 1895, in a cow’s head at Lyndhurst in August and in a mole in June; its cousin, A. gilvipes, was once found in a rabbit early in June, 1903.  A second kind of Braconid (? Rhogas sp.) was taken in the same kind of animal at the end of September, 1899; and a third, Meteorus filator, in a rabbit in November. ”  All that is from an old English publication, but it does validate that there are Parasitoid Wasps that will search for hosts on carrion.  We searched BugGuide for the genus Atractodes, and worked backwards to the subfamily Cryptinae, and BugGuide states:  “Mostly external parasites of pupae and cocoons; a few attack wood-boring beetle larvae, others attack larvae of Diptera, a few are hyperparasites of braconids and other ichneumons.”  We similarly searched Alysia on BugGuide and back to the Tribe Alysiini on BugGuide where it states:  “Often in moist habitats and decaying substrates, where host larvae are likely to be found” and “Larvae are parasitoids that feed on larvae of cyclorrhaphous Diptera (advanced flies with short antennae).”  We followed other links and did not find anything that looks like your Parasitoid Wasp, but we know we are on the right track.

Eric Eaton responds
Daniel:
Interesting.  Definitely one of the colorful Braconidae, and she is certainly ovipositing on *something.*
Eric
author, Kaufman Field Guide to Insects of North America
http://bugeric.blogspot.com/

Dear Daniel,
Thank you so much for your reply!  I’m so excited to hear from you.  Your second email is very informative and answers my question why the wasp was on the carrion.  This is the first time I posted my photo on any public website and I’m glad I did.  Hope to hear from you with the species name and I really appreciate your time and effort.
Kana

Update from Kana:  August 23, 2016
Dear Daniel,
BugGuide had a photo of wasp very similar to mine and it was taken in my area:  http://bugguide.net/node/view/464251
They filed it under subfamily Agathidinae.  The only thing is that they say it hosts Lepidoptera larvae and it doesn’t explain why mine was on rat.  But thank you for your help!
Kana

Hi again Kana,
The BugGuide information “hosts: Lepidoptera larvae” is so general it might not apply to all members of the subfamily.  Some parasitic Hymenopterans are not well studied and many have mysterious life cycles.  The BugGuide information might also be wrong.  Thanks for the update.

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Subject: Cool looking
Location: Michigan
August 11, 2016 4:29 pm
What is this thing in n michigan
Signature: John Peters

Giant Ichneumon

Giant Ichneumon

Dear John,
This is a Giant Ichneumon in the genus
Megarhyssa, most likely Megarhyssa macrurus.  It appears to be drinking from a water fountain.  Please confirm that.  Giant Ichneumons are sometimes called Stump Stabbers because the female uses her long ovipositor to lay eggs that will hatch into larvae that feed on the wood boring larvae of Horntails like the Pigeon Horntail.

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Subject: Wood eating mystery!!
Location: Southeast idaho
August 5, 2016 4:40 pm
Hoping you can identify this bug for me. I live in southeast Idaho and the other day I noticed a VERY loud chewing sound coming from a pile of branches I have in my backyard. When I went over to look all I could see was sawdust looking stuff all over, but I couldn’t find any bugs anywhere. Then today I noticed a few of these bugs flying around. I was nervous at first because it looked like a termite, but I’m not sure that’s what it is. It has a red body, black wings, and long straight black antennas. I’m really hoping it’s not a destructive wood eater.
Signature: Sarah

Braconid, we believe

Braconid, we believe

Dear Sarah,
While we are not able to give you an exact species identification, at least we can alleviate your anxiety by informing you that this is NOT a Termite.  We are quite certain that it is a Parasitoid Wasp, and after scouring the pages of BugGuide for the past two days, we believe it is a Braconid Wasp in the family Braconidae.  Our best guess at this time is that it might be in the genus
Atanycolus, which according to BugGuide is “Next to impossible to identify this genus from images alone, however it is one of the more common genera in the subfamily” and they are found in:  “Woodland habitats for the most part.”  BugGuide continues with this information:  “Parasites of woodboring beetle larvae, especially metallic wood-boring beetles (Buprestidae) and longhorn beetles (Cerambycidae)”  Here is a somewhat similar looking individual from BugGuide.  Now, here is our theory, though you did not say much about the pile of branches, we suspect the wood may have been infested with the larvae of wood boring beetles.  The beetles do make loud noises when they emerge from the pupa and chew their way to the surface.  The appearance of these Braconids is an indication that nature is trying to balance things out.  When hosts are plentiful, predators (or in this case Parasitoids) increase in number.  The female Braconid Wasp will lay her eggs, using her ovipositor, on or near the host, meaning the wood boring beetle larvae.  When the Braconid larvae hatch, they feed on the host, eventually killing it.  Adult Braconid Wasps eventually emerge from the wood and mate to produce a new generation.  So, while this Braconid Wasp is not feeding on the wood, it is trying to control some wood eating species of beetle.  That means something is eating your wood pile.  Finally, since the individual in your image does not appear to have an ovipositor, we suspect it is a male.

Braconid, we believe

Braconid, we believe

Wow, you guys are awesome!! You really know your stuff! After breaking apart some of the branches, I did find some beetles and larvae. You nailed it! And now I’ll just leave the wasps to feast away! Thanks again!

Thanks for the confirmation.

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Subject: Weird bug
Location: Denver
July 21, 2016 6:06 pm
Just in the ya4d collecting japanese beetles when we saw a very weird bug.
Signature: LouAnn

Therion morio

Therion morio

Dear LouAnn,
This amazing looking parasitoid Ichneumon,
Therion morio, does not have a common name. According to BugGuide:  “Host: moth larvae, including Hyphantria cunea (Fall Webworm).”  The female in your images is probably searching for caterpillars upon which to lay an egg so that her young can feed on the living caterpillar, eventually killing it.

Therion morio

Therion morio

What's That Bug? does not endorse extermination

Subject: Red mystery wasp
Location: near Ottawa, Ontario
July 18, 2016 3:43 pm
What is this beautiful little insect? I’m guessing some sort of wasp, maybe a parasitic wasp? I photographed it last week along Cedar Grove Nature Trail near Ottawa, where I see many fascinating tiny insects I can’t identify!
Signature: Suzanne

Ichneumon Stalks Caterpillar

Ichneumon Stalks Caterpillar

Dear Suzanne,
This is an amazing image.  We suspect that the Ichneumon Wasp, which you speculated correctly is a parasitoid, is stalking the Caterpillar.  Caterpillars are a common host to many species of Ichneumons.  Ichneumons are often very host specific, frequently limiting their prey to a single genus, or even a single species.  We are probably not even going to attempt to identify this Ichneumon beyond the family level as according to BugGuide, there are:  “About 5,000 described species in North America, possibly 3,000 more undescribed”  The caterpillar may be an Inchworm in the family Geometridae.

What's That Bug? does not endorse extermination