What's That Bug? does not endorse extermination

Caterpillar munching on chrysalis
Location: Rancho Bernardo, CA
December 8, 2010 1:46 am
Hello bugman,
This site is awesome! Please help identify this caterpillar that has been feasting on my Anise Swallowtail chrysalis. I found him on 12-5-10 tunneling through this chrysalis and also found a few other empty shells. I live in San Diego, CA.
Thank you.
Signature: cknapp

Cutworm and Chrysalis

Dear cknapp,
The caterpillar in your photo looks like a Cutworm, the caterpillar of a Dart Moth in the subfamily Noctuinae.  The odd thing is that in neither of your photos is any actual eating occurring, and the tail end of the Cutworm appears attached to the Chrysalis.  The Chrysalis also appears to have a hole indicating that it was parasitized by an Ichneumon.  We will not be tagging this as a Food Chain image because the evidence does not indicate that the Cutworm fed on a living Chrysalis.

Cutworm and Chrysalis: What is really happening here???

Thank you for the reply.  I have a screened cage where I have about 15 swallowtail chrysalis.  On Sunday I was cleaning out some plants when I noticed one chrysalis had a large hole in the side and it was empty.  That is when I discovered this ‘cutworm’ hanging out of another chrysalis.  When first found he was head first in the chrysalis with tail end hanging out.  I removed the chrysalis and cutworm from the enclosure, placed in a tupperware and took some pictures.  These first pictures showed the head inside the chrysalis and the tail end hanging out (it appeared to be eating).  Withing an hour it backed out of the chrysalis but it kept grabbing at the chrysalis and moving it around the tupperware container. Then it went back into the chrysalis and exited through the bottom of the chrysalis which are the pictures I posted.  I thought those pictures provided a better view of the ‘cutworm’ since the previous pictures I took only showed the tail end. I found the whole situation odd since I had never seen a hole this large and I did not see any wasps or indication of anything else that would have caused this.
I do appreciate your feed back.  Thank you so much.
Cindy

Thanks for the additional information Cindy.  Perhaps one of our readers will be able to provide some insight into this unusual phenomenon.

Karl solved the mystery (at least to our liking)
The Mystery of the Cutworm and the Chrysalis – December 8, 2010
Hi Daniel and Cindy:
It is a Noctuid moth but the subfamily is Heliothinae. It looks like a Corn Earworm (also Cotton Bollworm and several other common names), Helicoverpa (=heliothis) zea.  The caterpillars come in a wide variety of colors and they change color as they progress through their moults. They are considered a very serious pest on many agricultural crops, although they apparently favour corn. The question of course is, was he caught in the act or was he an innocent bystander?  Well, if any caterpillar could commit such a crime, this would probably be it.  These are aggressive little guys with predatory tendencies and a reputation for cannibalism.  According to one report (Chilcutt 2006), cannibalism may in fact be the most important mortality factor for H. zea.  Predation on other species also has been reported, but appears less common.  If he didn’t do it, perhaps he was just sniffing around for leftovers.  Regards.  Karl

Wow Karl,
This is like an Agatha Christie episode of the insect world.  Cannibalism in Caterpillars, and then out and out predation of a harmless slumbering chrysalis.  After Cindy’s last email, I had already reconsidered the reluctance to tag this posting as “Food Chain“.

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What's That Bug? does not endorse extermination
Location: California

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