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Isodontia Cocoons in the track of my window screen - Isodontia

Isodontia Cocoons in the track of my window screen - Isodontia
Raleigh, near Rts 50 and US 70, Wake County, North Carolina, USA
October 20, 2009
Size: 22mm
I have seen these for many years, but don't know what kind of insect is the adult. The cocoon is 22 mm and includes wings. Inside is a dark case with a 13mm yellow larva/pupa? (soft and moves). Amid the grass, juniper and pine needles are some dead click beetles and insect legs as well as wings.

Images of this individual: tag all
Isodontia Cocoons in the track of my window screen - Isodontia Cocoons in the track of my window screen - Isodontia Cocoons in the track of my window screen - Isodontia Isodontia cocoons in the track of my window screen - Isodontia Cocoons in the track of my window screen - Isodontia Isodontia wasp newly hatched.  I mexicana? - Isodontia Isodontia wasp newly hatched.  I mexicana? - Isodontia

I also have the same thing in
I also have the same thing in the track of my windows...each year i clean them out with the vacuum cleaner....I always thought they were from stink bugs. I guess not. Seems like the stink bugs appear in my house the same time. Thought the little green like grasshopper maybe turned into the stink bug. Is there anything else we can do about this??

Treasure them!
Forget the vacuum cleaner treatment and let them be. They are eating your stinkbugs or other related pests so they are good to have around.

Isodontia Cacoons in the track of my window screen
We find the same cocoons in our window screen tracks every year at this time although I haven't seen any adult isodontia yet. We also see small green winged insects with long legs resembling grass hoppers along side the cocoons and in the dried grass. We live in New York about 60 miles north of NYC.

Finally, an answer to what this is!
Hi, I also live north of NYC, but in CT, about 50 miles from midtown. Anyway, I have been trying to figure out what these straws in my screen rails are, and now I finally know! I did not know until this week that there were cocoons inside the rails though, and I did find a few. Even though it's winter, I had to lean out the window to clear some icicles (long story). Perhaps a couple of the cocoons got caught on my clothing as I was leaning out, because I found 2 in the clinging to a velvet window curtain at about chest level, which makes sense if it was stuck to me, and one laying on a hardwood floor in a room where I did clear icicles out the windows.

We love to have our windows open in the spring/summer...and never had had a wasp problem indoors...could it be that the wasps just use the rail, and go in and outside as they please, and don't want to bother with us inside? I have been noticing the straw remnants since we moved here in 2006 (house is 55+ years old). But only in a few windows...which happen to be in the bedrooms. Our bedroom gets all day sun so that is probably why?

Having said that, I would like to find a remedy, but I don't see where we could plug any openings, as I don't see any gaps, and the screen is always down, so I don't see how they get into the rail to begin with. Would love to avoid pesticides as I did read these are helpful in eradicating other outdoor pests. But I really am not too keen on wasps coming in and out of our bedroom screens, especially since we have the windows open a lot in spring and fall (not as much in summer but still sometimes if it's cool enough). Any tips?

By the way, it's the middle of January and we just got 2 feet of snow, is there any way these are active cocoons, or did they not survive the winter? Thanks, Dan

Why do you want to kill them?
Are they causing you any trouble? If not, let them be. They catch other insects, mostly Grillidae and Orthoptera, as you can see here. So you could say that they are useful pest controls. I understand that they are not likely to sting.
They stock the cell with some food and lay an egg. The larva feeds and grows and spends the winter inside the cocoon. The adult emerges the next summer to start all over again. You can read more in the info page

Yup, ours are stuffed again.
I was away the month of June. Just noticed in early July that the screen tracks are stuffed with grass again, grass sticking out this time over the glass of the window by this computer, not confined neatly to inside the track as in past years. Usually I don't know the insects have been busy until I open the windows in Fall. Oh, the younger generation has lost its skills... Susan in Raleigh NC


Worth linking
To the adult that emerged from one of these

How do I do the linking?
How do I do the linking?

I did it for you this time. Next time, to link photos of the same specimen you tag them all in the sequence you prefer; they will show up in the upper left and there will be the word "link" underneath. You just click on it.
Nice life series.

Temperature for Isodontia cocoons?
My husband reports that when he was cleaning gutters he saw a wasp bringing grass and stuffing it under a roofing shingle.

By the way, we haven't had frost yet and will go many years without any as close to the heat of the house as the window-screen track is, a couple inches outside the double pane windows. The larvae in natural conditions must be in the dark but are they protected from freezing over the winter? Is the grass for insulation?


Moved from ID Request.
The dark thing attached to the unopened cocoon looks like a fly puparium... presumably a tachinid or sarcophagid that parasitized the wasp larva in that cocoon.

Check out grass-carrier wasps...

Isodontia sure looks right, thank you.
I had no idea where to start looking, but with your direction I found lots of references. Now I'll start looking closer for the adult wasps of Isodontia since they sip nectar. Wonder what the Melanotus click beetles were doing there; that doesn't seem to be the usual prey.

I wouldn't think the beetles are prey, as they remained intact after the wasp larvae spun their cocoons. Otherwise, they'd be pieces/parts like the tree cricket legs and wings.

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