Currently viewing the category: "Parasitic Hymenopterans"
What's That Bug? does not endorse extermination

Subject:  This bug / insect scares me
Geographic location of the bug:  Goodlettsville TN
Date: 07/11/2018
Time: 07:05 AM EDT
Your letter to the bugman:  This see picture has shown up on my front porch. It flies quickly if you try to get near it. Is it harmful or dangerous? It scares me.
How you want your letter signed:  Karen

Stump Stabber

Dear Karen,
The Giant Ichneumon or Stump Stabber is neither harmful nor dangerous, but the lengthy ovipositor is frightening looking.  This is a beneficial insect.  The female uses her ovipositor to lay eggs beneath the bark of trees infested with wood boring larvae, and the Ichneumon larva feeds on those wood boring larvae.

What's That Bug? does not endorse extermination

Subject:  Unknown hymenopteran
Geographic location of the bug:  south eastern PA
Date: 07/10/2018
Time: 04:35 PM EDT
Your letter to the bugman:  Hello. I am the plant protection intern at Morris Arboretum of the University of Pennsylvania and our arborist saw this insect fly out of a diseased Juniper. Can you please help me to ID it? I am sorry that he removed the insect’s head. I took this video because it is still moving.
Thank you.
How you want your letter signed:  Jenny

Braconid, we believe

Hi Jenny,
Because of the coloration, what appears to be a long ovipositor at the tip of the abdomen, and the written description that it emerged from a diseased juniper, we believe this is a Braconid, a parasitoid Hymenopteran in the family Braconidae, which is well represented on BugGuide.  We have an old posting of Braconids swarming on a grape trunk in California, and at that time, Eric Eaton noted “so few braconids are parasitic on wood borers.”  We also have this UK sighting in our archives that we believe to be in the genus
Atanycolus.  That genus is represented on BugGuide where it states:  “Parasites of woodboring beetle larvae, especially metallic wood-boring beetles (Buprestidae) and longhorn beetles (Cerambycidae).”  Since your juniper is diseased, it is probably infested with wood boring beetle larvae, the natural prey for parasitoid Braconids in the genus Atanycolus, so your arborist seems to have decapitated a beneficial predator and part of the solution, and not the cause of the problem for the tree, which is why we will be tagging the posting as Unnecessary Carnage.  If the tree does have a bad infestation of borer grubs, you might see additional Braconids emerge.  The female Braconid uses her ovipositor to deposit eggs beneath the bark of an infested tree or other woody plant, and the hatched larvae feed on the larvae of the beetles.  Adults emerge after pupation, so it is an understandable mistake to believe the Braconid is a harmful insect when it emerges from the tree.  We hope the information we provided will score you a few extra intern points.  

Great. Thank you so much for the very detailed response. It was sad to see that a good insect was decapitated, although it was an honest mistake. I was not there when it happened 🙁 I realized that my post still said video, even though I sent a picture. I was unable to upload the video file to the site because it was too large, but I have attached it here. It is very unsettling, especially when the poor wasp’s wings move.
Jenny

Braconid Wasp

Thanks Jenny,
We were able to get a better still from the video to illustrate the posting.

What's That Bug? does not endorse extermination

Subject:  Is this some kind of wasp?
Geographic location of the bug:  Rural Upstate NY
Date: 06/25/2018
Time: 09:46 AM EDT
Your letter to the bugman:  This bug was trapped inside our screened porch June 20 this year. It was over 2 inches long.  Thanks…
How you want your letter signed:  Matt

Stump Stabber

Dear Matt,
This is a harmless, parasitic Giant Ichneumon in the genus
Megarhyssa, a group commonly called Stump Stabbers because the female uses her long ovipositor to lay eggs in stumps and trees that have infestations due to wood boring larvae that provide food for the larval Stump Stabber.  Ichneumons are classified in the same insect order as Wasps, Ants and Bees. 

What's That Bug? does not endorse extermination

Subject:  Weird flying bug
Geographic location of the bug:  West Yorkshire UK
Date: 06/23/2018
Time: 05:06 AM EDT
Your letter to the bugman:  Hi this was in my garden this sunny morning, any clue what it is?
How you want your letter signed:  Sam

Carrot Wasp: Gasteruption jaculator

Dear Sam,
We found your parasitic Hymenopteran pictured on Nature Spot where it is identified as
Gasteruption jaculator.  According to the site:  “The female will visit the nests of various solitary bees or wasps, and will push her ovipositor into the nest, depositing her own eggs on or near to the eggs of the host, on hatching they will feed on the grubs of the host as well as on stored food.”  The Game and Wildlife Conservation Trust has this lengthy description of the process:  “The female finds nests of various solitary bees or wasps, and will then spend some time assessing each hole. She does so, it is thought, by feeling for vibrations from the grubs moving around inside, as the nest hole will have been blocked up to protect the grubs. Having decided on a suitable nest hole, she pushes her long ovipositor through the blocked-up entrance into the nest, depositing her own eggs next to the bee grubs. Very soon the eggs hatch and immediately the young start to feed on the grubs within the nest. They will also consume the food larder of pollen and nectar, left there for the bee grubs to feed on.  The fully grown larvae stay in the bee hole over winter, pupating in the spring and hatching out from May through to September, so they can be seen throughout the summer months, nectaring on a range of plants. This long summer hatching period enables the female to choose a wide range of solitary bee and wasp hosts to target for raising her own offspring, ensuring that her eggs are quite literally not all in the same basket. It also means that they can, to a certain extent, avoid being attacked themselves by other parasites, which might be the case if they all hatched at the same time.”  Neither of those sites provides a common name, but the collective common name on the North American site BugGuide is Carrot Wasp.

What's That Bug? does not endorse extermination

Subject:  What is that wasp?
Geographic location of the bug:  Mountains by provo Utah
Date: 06/16/2018
Time: 02:09 PM EDT
Your letter to the bugman:  We saw several very big wasps while camping in the mountains next to provo Utah. At first we were a little afraid of them do to their size, but eventually we realized they were not interested in us. We saw them mostly on the trunks and branches of the trees in small groups. Their body’s were long and slender, at least 2 inches long, with long legs. They had a “stinger” that was twice as long as its body, but really mobile and bendable. Just curious what it might be. We have lived in the city at the base of the mountain for decades and have never seen them before.
How you want your letter signed:  Curious Canpers

Stump Stabbers

Dear Curious Campers,
These are female Ichneumon Wasps in the genus
Megarhyssa, commonly called Stump Stabbers because they use their long (up to five inches long) ovipositors to lay eggs in trees and stumps that are infested with wood burrowing Horntail larvae.

Stump Stabbers

What's That Bug? does not endorse extermination

Subject:  What is this
Geographic location of the bug:  Montreal , Quebec
Date: 06/11/2018
Time: 07:06 PM EDT
Your letter to the bugman:  We found this on a diseased Maple tree in our backyard.  Can you identify what this is
How you want your letter signed:  Alan Kelly

Giant Ichneumon Ovipositing

Dear Alan,
This is a female Giant Ichneumon in the genus
Megarhyssa, probably Megarhyssa macrurus which is pictured on BugGuide, and she is ovipositing or laying eggs.  Since you have indicated that your maple tree is diseased, it is most likely infested by various wood boring insects, including the larvae of the Pigeon Horntail, the prey of the Giant Ichneumon.  The female Giant Ichneumon senses the presence of the larval Pigeon Horntail burrowing in the wood, and she inserts her long ovipositor so she can lay an egg on or near the larval Horntail.  When the egg hatches, the larval Giant Ichneumon will parasitize the Pigeon Horntail larva.  The Giant Ichneumon will not harm your tree.

What's That Bug? does not endorse extermination