Fratricidal caterpillars?

Factual Questions
1

This spring we bought our daughters a kit to raise butterflies from caterpillars. The whole process went well and 9 of the 10 caterpillars successfully turned into butterflies (Painted Lady I think). The 10th formed a chrysalis but never emerged.

The kids liked it so much they asked me to order a refill of caterpillars to do it again. But this time it hasn’t gone so well. All the caterpillars did their thing and started making crysalides. In one jar (which had 5 caterpillars), I first saw three chrysalides hanging and the two remaining larvae still walking around. A few hours later when I checked again, I saw a fourth caterpillar in a chrysalis but two of the other chrysalides had fallen. I thought this was odd. But then the same thing happened in the second jar. Four caterpillars formed chrysalides at first with one larva remaining (it was much smaller than the others from the beginning). A couple of days later I saw that two of the chrysalides had fallen. I think the 5th caterpillar did it. I should add that the jars have not been moved in any way during this whole time.

So all I can conclude is that the caterpillars that were still in larva form had accidentally/deliberately knocked down the others once they were in their vulnerable chrysalis state.

Is this a thing?

On a related point, is there anything I can so to save the chrysalides that have been knocked down?

2

I didn’t know this and find your OP very interesting. Here is an interesting article on this subject.

Why would a caterpillar eat another or a chrysalis?

3

Fratricidal Caterpillars? Band name.

Just superglue them in place by the “stem.”

4

That’s the answer. Before Hurricane Irma destroyed it, we’d spend a day every year at St Martin’s Butterfly Farm in the Quartier D’Orleans. Thousands of butterflies all hanging out in a huge net building. They constantly handled chrysalides, gluing them in place at the location that worked best.

5

thanks. Just tried it. Hope it works (just saw there isn’t a superglued chrysalis emoji. What were they thinking?)

6

that is really informative. I am not completely sold on the ‘you are what you eat bit’, and no one has eaten anyone so far, but it’s interesting to see that such negative behavior exists.