Sycamore Tussock Moth Caterpillar with Parasitoid Pupae

Subject: Is this an American Daggar Moth Caterpillar?
Location: Cleveland, OH
August 8, 2014 5:28 pm
I have seen so many of these caterpillars this year in my backyard! I think this is an American Dagger Moth Caterpillar, but why does it have these weird things on its back? All of these caterpillars are surrounding my pool and sometimes fall in.
Signature: MissX

Sycamore Tussock Moth Caterpillar with Parasitoid Pupae
Sycamore Tussock Moth Caterpillar with Parasitoid Pupae

Dear MissX,
In our opinion, this is a Sycamore Tussock Moth Caterpillar,
Halysidota harrisii, and it is host to the pupae of a parasitoid wasp, most likely a Braconid.  Parasitoid Wasps are often very host specific, preying upon a single species or genus.  Parasitoids feed on the internal organs of the host species, eventually killing the host.  See this matching image on BugGuide and this matching image on BugGuide.

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bugman

BugMan aka Daniel Marlos has been identifying bugs since 1999. WhatsThatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

4 thoughts on “Sycamore Tussock Moth Caterpillar with Parasitoid Pupae”

  1. We noticed a very similar caterpillar today–near a sycamore tree. It had many more egg-type sacs on it. They almost looked hollow. Could the wasps have hatched? Near Indianapolis, 9/4/14
    Zionsville, In

    Reply
  2. We noticed a very similar caterpillar today–near a sycamore tree. It had many more egg-type sacs on it. They almost looked hollow. Could the wasps have hatched? Near Indianapolis, 9/4/14
    Zionsville, In

    Reply
  3. I have collected some tussock moths from guava plant. I reared it and found parasitoid those had long filliform antennae. Abdomen consists of 11 segmented with alternate white and black colored segments alternately. Please try to send me the name of parasitoid

    Reply

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