What's That Bug? does not endorse extermination

Subject: paralized grasshoppers in nest above my door?! Could they be victims or wasps?
Location: Andover, MA
July 2, 2012 7:53 pm
I opened my screen door and out drops dozens of small green grasshoppers (not sure what kind) onto my head!…
They are alive but not able to move very much. My guess is they were parasitized by a wasp. If this it true, I’m assuming wasp eggs were laid in these pretty little things.
I would love to know for sure!
Thanks BugMan!
Signature: covered in grasshoppers

Paralyzed Drumming Katydid Nymph

Hi Roberta,
We will be writing to both Piotr Naskrecki and Eric Eaton to try to get to the bottom of this food chain mystery.  These are not Grasshoppers because their antennae are too long.  They are some immature Longhorned Orthopteran in the suborder Ensifera.  The specimen in hand appears to be a juvenile female because of the presence of an Ovipositor.  Perhaps Piotr who specializes in Katydids can provide species or genus information.  Thank you for including the nesting material.  It is most unusual and we do not know of a Parasitic Wasp that uses straw to build a nest, but perhaps Piotr or Eric will know more on that subject.

Paralyzed Drumming Katydid Nymphs with nesting material

Piotr Naskrecki identifies Katydids
Hi Daniel,
Cannot tell you much about who paralyzed these katydids (my guess would be a sphecid wasp of some kind), but the insects themselves are nymphs of Meconema thalassinum, a European species, introduced and now common in the Eastern US.

Ed. Note:  BugGuide identifies Meconema thalassinumas the Drumming Katydid.

Cache of Katydids from Nest

Eric Eaton provides a likely Predator:  Grass Carrier Wasp
Hi Daniel, Piotr:
Very interesting!  The wasps building the straw nests would be “grass-carriers” in the genus Isodontia, family Sphecidae.  I think the host here would be a new record since the wasps are native but the prey is not.  There are at least three or four Isodontia spp. in Massachusetts, so without at least an image of the wasp we can’t make an association.

Update from Roberta:  Larvae Emerge
Hi Daniel,
Thanks for the response. Larvae have started emerging from the katydids.  I have attached a couple of photos.  I did the best I could without a macro lens.
I have wasps buzzing around my house with little pieces of straw in-hand.   So a wasp came to mind as the culprit when the katydids dropped on my head.
They are still on my deck;  I would like to put them out of their misery if that’s okay?
Thanks again!

Wasp Larvae emerge and feed on Katydids

Ed. Note:  We missed Roberta’s first update and we added them to the original posting out of order.
Hi Roberta,
We somehow missed your first update.  While we understand the sympathy you feel for the Katydids, we can’t help but to marvel at the cache of Drumming Katydids that the Grass Carrying Wasp assembled and we hate to see that effort go to waste.  We wish you could provide a suitable substitute habitat and let nature take its course.

Update from Roberta:  Photo of the predator
Hi Daniel,
I attached a photo of the wasp .  I believe this is the species of wasp that is parasitizing the Drumming katydids.   There were a number of these wasps flying around carrying pieces of grass.  This one, however, isn’t.
I hope this helps.

Grass Carrier Wasp

Hi Roberta,
We feel we are making a conviction based on circumstantial evidence, but we are nonetheless pleased to arrive at the same conclusion that you have:  that this Grass Carrier Wasp or one of its relatives built the grass nest that was provisioned with immature Drumming Katydids.  Thank you so much for the follow-up.  This is exactly the type of interactive posting we love, complete with expert testimony.  Additionally, through a continued effort on your part, you photographed the interconnectivity between these two species, the predator and the prey.  It should be noted that like other wasps that prey upon insects, it is done for the purpose of feeding a brood.  The adults feed on nectar, most likely because during the evolutionary process, parents that did not compete with their young for the same food supply produced more offspring since food did not have to be shared.

Hi Daniel,
The scientist in me decided to let nature take its course; I placed the katydids in a covered area of my yard.
I kept one of the katydids to follow the development of the Grass Carrying Wasp.
I will let you know if I am successful in raising the wasp to adulthood.
Thanks so much for your wonderful site.


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What's That Bug? does not endorse extermination
Location: Massachusetts

32 Responses to Paralyzed Drumming Katydids found in Nest of a Grass Carrier Wasp

  1. hutch says:

    I found the same thing on my windowsill just now in Bennington VT. This site was very helpful.

  2. Frances Benemowitz says:

    I was cleaning my porch windows and found straw stuffed in the left (south) track of six windows. Some of the nests had four or five Katydids in them. I thought the nests were the work of birds until today, when I actually saw one of the wasps flying around holding a Katydid and then trying to stuff it into a hole in a patio chair. The wasp looks like the one in the picture. I am in Essex County, New Jersey.

  3. Deborah Tyler says:

    I found so many nest made of dried grass with grasshopper looking critters in them in different stages, some young and barely moving and some that were completely dehydrated and something in larvae stage in the folds of my out door umbrella. I cleaned them out once and it was a mess and about 2 weeks later there were many more, so I have left my umbrella opened. I am in Tyler, Texas and have never seen this before. They need to move on. Just sayin…….

  4. Misty Scott says:

    I live in Knoxville, TN and my 90 year old grandmother has been perplexed for years over this phenomenon. She couldn’t understand why a black wasp-like bug would build a nest in the left side crevices of her window frames filled with grass/hay. When she would take the screen out of her window and scrape the grass out, many grasshoppers/katydids would fall to the ground. They were alive but couldn’t move. She has been convinced for years that those katydids were baby wasps. I’m happy to tell her about what has really been happening. I do have a question though. Why do they only build on the left side?

  5. BGreene says:

    Today I found two such nests in the bottom frame of my screens. It made no sense that the little green “worms” could build on the second floor. Then I uncovered a live wasp in the grass nest. I live in Rochester, NY.

  6. Krista says:

    I found a nest built right into the door of my car with at least 10 tiny green victims, and I have also seen adult wasps around/in that crevice. I want to relocate everything somewhere less volatile (or likely to bake in the sun); what are environmental factors I should watch for to keep them safe?

  7. Carmsco says:

    I have been finding these nests in my crank out windows for 5 years now… filled with katy dids inside grass nests – sometimes 10-15 on a window, along with larvae – and occasionally will see the black wasp tucked in there with them when I open my window. If I don’t open them often, they will be packed, both on the bottom sill and the top of the window getting cranked out. Our windows face north and west… and it is on all of them. We live in Foreston, Minnesota… I only see them in the spring/summer months.

  8. Abbey says:

    Hi everyone – this is helpful! Our grass carrying wasps I believe have set up camp in our backyard door in Toronto. I’m hoping to move them this weekend eeks – will they come right back when we shut the door and go to work?

  9. Amy says:

    Hi everyone, I am so glad to come across this info! My daughter just showed me a bunch of grasshoppers jammed into the side of my screen, one was in the will just barely moving. Thanks to you I know what is going on! But question how to get rid of these “creatures” before I have wasps buzzing around by bedroom? Should I just use wsdp spray? I live just outside of Boston, MA and have NEVER seen this before!!
    Thanks again for the help.

  10. Steve says:

    I’m in Oregon, (Portland area) and I stumbled across this when searching for a reason why my hoses and sprayers keep getting clogged up with grass and what looks like little bright green grasshoppers or crickets! I keep buying my plant watering devices only to find out they are plugged up right away, so I look inside to find these things.

  11. Jennifer says:

    Yes! Thank you! Been wondering what was going on here! Always in our south facing windows at the top! Simsbury CT

  12. Pam says:

    You certainly answered my question as to what these things were. I first noticed the small clumps of grass and little green nymphs on my deck furniture. The wasps are building their nests up under the siding on my home. This is the first year I’ve had them. My problem is the tiny black ants that converge on the little green nymphs as soon as they fall out.

  13. Sharon Barrows says:

    Yep! Just what I thought about those little green bugs. Thanks for all the information and pictures.

  14. William says:

    I also live in the portland oregon area, aloha, and have found huge numbers of these nests in stored cedar shingles I’ve been processing. I’ve never seen the wasps but I’ve been able to watch the nests change from twitching katydids and grass into piles of legs and wings with pupae. Interesting they’re packed in grass. Thank you so much for identifying this awesome and bizarre phenomenon!

  15. Nancy says:

    I am in Toronto, Canada and found two of these nests last night just outside my window too ! totally freaked me out as I had no idea what it was ? grasshopper nest was my first thought but too high up for that. There was also one of those black wasps by one of the nests too ! I took photos as I was completely amazed at the little pods built for the larvae…wish I could upload but not sure how?

  16. Adrienne says:

    I just saw some little strands of dead grass on my daughters windowsill the other day. I cleaned it up and looked again a day later and there were three of the katydids in the window next to her air conditioner. I got rid of them (not knowing what they were) and 5 minutes later there were 2 more. I was so confused and it looked like another one inside the right track of the window. For now, we stuffed an old t-shirt in the space and put tape around it to keep any bugs out of the house. This is so interesting though! I am in Schenectady, NY.

  17. Melissa A says:

    Thank you for this article. I had not driven my car in a week and when I opened my door, all these baby grasshoppers fell out with dead grass/straw material.
    They were in the top door jambs of all 4 doors.
    I had no idea what was making the nests but wasn’t amused by them at all. I have lived on farms all my life in Middle Tennessee but never remember having this happen before. At least not on my car.
    I don’t mind bugs in general but Hate spiders! So I was relieved to know the nests were caused by wasps and not some creepy spider.

  18. Gayleen says:

    I’ve lived in this house 14 summers and have never witnessed this prior to this year! So interesting! Five-ten nymph katydids each day on porch. Grass carrying wasp nests in tubes of windchimes! So glad I found this thread!

  19. Gayleen says:

    Oh! Forgot to mention Ogden, UT

  20. Amy P. says:

    I was so traumatized at having disrupted a “grasshopper nest” when I opened my car door! The babies were still too little “to move much,” so I closed the door back up. I’ve been worried about them for two days, so finally googled and learned about their nightmare! Horrifying. I raced outside and put them out of their zombie’d misery. And to learn they were little Katydids, too. 🙁 I know Nature is Nature, but I couldn’t sit by for that one.

  21. yvonne Meyers says:

    I have been dealing with this for 3 yrs now. don’t how to stop it. none of my neighbors deal with these. I live in Imlay City Mi.

  22. Fiorella Pachone Hidalgo says:

    Hi, I had the exact same case, I opened my window and I could see the prepature Drumming Katydids and hints of wasp eggs on their bodies.
    Is it dangerous to have them so close to the house?

  23. Susan says:

    I live in upstate New York. In the past week, I’ve had 4 nests in the rubber trim on the inside of my car doors. I do not know how they get into the car doors. When I open the car door, the wasp flies out and the nests are visible. Any suggestions on how to stop it? I feel badly destroying the nests but I can’t leave them there.

  24. Tess says:

    So glad to find your site! Cleaned windows this morning and a nest of these dropped down into my study (south window) along with a wasp totally freaking me out. First time this has happened. Will be much more alert next year. Wondering why now? Thanks for the education. We live in Avon, CT.

  25. Annemarie says:

    Wow just found all these barely moving katydids on our outdoor table so happy I came upon this!
    Yesterday I did see a wasp pull a ( what I thought was a grasshopper) into a whole in the pole on our deck near the table where tonight I found six more seemingly paralyzed!
    Glad to know it wasn’t some insecticide in the area! Thanks again!

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