JungleDragon is a nature and wildlife community for photographers, travellers and anyone who loves nature. We're genuine, free, ad-free and beautiful.

Join

Parasitoid Wasp - Subfamily Braconinae On 8/2/25, I spotted a bunch of Acharia stimulea caterpillars on oak (Quercus). They were very vibrant: <figure class="photo"><a href="https://www.jungledragon.com/image/170739/saddleback_caterpillars_-_acharia_stimulea.html" title="Saddleback Caterpillars - Acharia stimulea"><img src="https://s3.amazonaws.com/media.jungledragon.com/images/3232/170739_thumb.jpg?AWSAccessKeyId=05GMT0V3GWVNE7GGM1R2&Expires=1759968010&Signature=FaPFDMi%2BNEvO3s4pHB8SYJVDw74%3D" width="200" height="160" alt="Saddleback Caterpillars - Acharia stimulea Host: Quercus Acharia stimulea,Geotagged,Saddleback Caterpillar,Summer,United States,acharia,caterpillar,larva" /></a></figure><br />
<br />
But, one caterpillar was pale. I thought that maybe it had recently molted and was in the process of darkening. Out of curiosity, I took it home to rear.<br />
<br />
By 8/8/25, the caterpillar had stopped moving. But, I could see something moving INSIDE of it. The caterpillar itself looked like an empty shell that was housing something...<br />
<br />
On 8/16/25, a wasp emerged from the parasitized caterpillar. I preserved the wasp in 70% EtOH and am hoping it can be IDed at some point.<br />
<br />
Videos that show the developing wasp moving inside the caterpillar. These videos are not dramatic, but you can see the slight movements:<br />
<section class="video"><iframe width="448" height="282" src="https://www.youtube-nocookie.com/embed/GII4h_R5vEM?hd=1&autoplay=0&rel=0" frameborder="0" allowfullscreen></iframe></section><br />
<br />
<section class="video"><iframe width="448" height="282" src="https://www.youtube-nocookie.com/embed/GNYmAiahMwY?hd=1&autoplay=0&rel=0" frameborder="0" allowfullscreen></iframe></section><br />
 Acharia stimulea,Caterpillar,Geotagged,United States,braconidae,braconinae,parasitoid,wasp Click/tap to enlarge

Parasitoid Wasp - Subfamily Braconinae

On 8/2/25, I spotted a bunch of Acharia stimulea caterpillars on oak (Quercus). They were very vibrant:

Saddleback Caterpillars - Acharia stimulea Host: Quercus Acharia stimulea,Geotagged,Saddleback Caterpillar,Summer,United States,acharia,caterpillar,larva


But, one caterpillar was pale. I thought that maybe it had recently molted and was in the process of darkening. Out of curiosity, I took it home to rear.

By 8/8/25, the caterpillar had stopped moving. But, I could see something moving INSIDE of it. The caterpillar itself looked like an empty shell that was housing something...

On 8/16/25, a wasp emerged from the parasitized caterpillar. I preserved the wasp in 70% EtOH and am hoping it can be IDed at some point.

Videos that show the developing wasp moving inside the caterpillar. These videos are not dramatic, but you can see the slight movements:



    comments (4)

  1. Superb documentation. I've read about the process so many times but never actually saw it. Thank you for putting in the time! Posted 10 days ago
    1. Thanks! I would have liked to see it actually emerge, maybe next time. I seem to collect more parasitized insects than not. Posted 8 days ago
      1. I wonder if that's bad luck or consistent with statistics that may suggest only a minority survives? Posted 8 days ago
        1. I'm not completely sure. But, from what I've been told, it seems fairly normal. Posted 6 days ago

Sign in or Join in order to comment.

No species identified

The species on this photo is not identified yet. When signed in, you can identify species on photos that you uploaded. If you have earned the social image editing capability, you can also identify species on photos uploaded by others.

View Christine Young's profile

By Christine Young

Attribution Non-Commercial
Uploaded Aug 26, 2025. Captured in 91 Main St, Sharon, CT 06069, USA.