Spongy moth treatment - Ask Extension
I successfully treated our home owners association with parasitic wasps last year. We are preparing to use the same tricogramma brassicea wasps as la...
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Spongy moth treatment #868566
Asked May 15, 2024, 2:16 PM EDT
I successfully treated our home owners association with parasitic wasps last year. We are preparing to use the same tricogramma brassicea wasps as last year. I just don't know when to put out the first application. Can you give me advice as to when to put it out? I think our caterpillars are in the 3rd instar.
Kalamazoo County Michigan
Expert Response
You're correct that there are 2 parasitoid wasps that attack spongy moth. However, neither are Trichogramma, and I'm not aware of them being available for purchase commercially. Both occur naturally and aren;t easy to predict exactly where they are.
Now is the correct time that parasitoids would be laying eggs within spongy moth caterpillars.
Now is the correct time that parasitoids would be laying eggs within spongy moth caterpillars.
I think you must have been answering someone else's question. I never mentioned 2 parasitoid wasps. I specifically stated that we had treated successfully last year with trichogramma brassica and wondered when would be the best time to put the eggs out. Since our caterpillars are only at 3rd instar, I'm afraid this is too early. Perhaps around 6/5??? I don't think they lay their eggs in the caterpillars?? They lay them in the moth eggs??
Cara Terry
The spongy moth adults don't lay eggs until July or August. Releasing those trichogramma in June would be too early. I'd suggest waiting until 2nd or 3rd week of July. Since T. brassica are generalist parasitoids, they can also attack other species of caterpillar eggs in the area.
Apologies for the confusion earlier.
Apologies for the confusion earlier.
