Possible Wasp Infestation in Swallowtails

by Cathy

I asked this question before, but perhaps you did not get it. I have chrysalis from late fall (swallowtails). I noticed tiny wasp like bugs dead in the bottom of the cage last fall. Are my chrysalis infected? How can I tell? Would they all be infected? How to prevent this this season?

Karen says:
A caterpillar can be host to the larva of a fly or wasp. Brown spots can develop on the caterpillar. Fly pupas (which are small ovals which are white then turn dark) come out of a chrysalis.

Wasps usually hatch and exit out of the monarch chrysalis, leaving an ugly hole. Can you see a hole in the chrysalis?

Hope this helps.

Comments for Possible Wasp Infestation in Swallowtails

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Swallowtail Update
by: cathy

I have had 3 of the chrysalis hatch, 4 to go, I am hopeful the little wasp like insects did not infect any of them. I will take the advice to wash the frass off when I start raising them this year.

Wasp infestation
by: cathy

Today I had the first chrysalis hatch with a swallowtail emerging. I have several still to hatch, I wonder if some may be infected, I did not know the wasp overwinter too. How long should I give the others to hatch before discarding them?

Karen says:
Since you just had a swallowtail emerge, I would give it a couple more weeks. Overwintering swallowtail chrysalis seem to vary quite a bit on emergence times. I would make sure and sterilize everything you are using for raising butterflies with a 20% bleach solution once you are done with these.

by: Betsy

I just had a wasp hatch out of an overwintered swallowtail pupa....they are parasitic wasps I believe and feed on the caterpillar in the pupa...disappointing to expect a butterfly only to get a nasty wasp!

Pupal wasps
by: Anonymous

One way to protect your caterpillars from wasps is to make sure that you wash the Frass off your plants since it attracts pupal wasps

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