This is a GQ, but it was prompted by a staff report here so I provide the link for reference.
Basically, the report says that a caterpillar in a chrysalis pretty much completely disintegrates, except for a packet of larval tissue, which then assimilates the disintegrated organic matter into a butterfly.
I assume from this description that it is impossible to teach a caterpillar anything that can subsequently be remembered by the butterfly it turns into.
But I am just checking here to make sure my inference is correct. Also, to ask to what extent it applies to various metamorphosing species.
Also, does anyone ever argue that the butterfly and the caterpillar ought to be considered to be two different organisms? Not sure what the practical upshot of such a notion would be, but just curious if anyone has said it.
No, you can teach them. For example, cockroaches can be given olfactory conditioning. cite. Though I could have sworn this was well known already, yet that study says it’s the first to show this, and it’s only from 2003.
I swear on God and Jesus that I’d read about roach olfactory conditioning way back in high school, though, so I don’t know if I’m crazy or something.
However, given the very different body organization, I doubt whether a butterfly could retain anything much learned in the caterpillar form. I could imagine, though, that some preference for a particular food plant could be retained (though this could possibly be transmitted chemically rather than neurally).
In high school, we trained sow bugs.
Using a bright light, which they avoid, we ran the sow bugs down a T shaped ‘maze’. Ten runs or so with each bug showed that each bug preferred to turn one direction (right or left) over the other. Once we identified each bug’s tendancy, we used the light to encourage them to go the opposite way. After training, most of them tended turn the opposite direction that they had once preferred.
For one thing, the female butterfly has to know on which plants to lay her eggs, so the emerging caterpillars will be on a plant appropriate for their diet. But I don’t think this knowledge is acquired through her memory of having been a caterpillar.
Most likely not. However, some butterfly species feed on a range of host plants as caterpillars. Offhand, I don’t know if there is a tendency of a female to lay on the same host plant species she herself fed on (not just the range of host plants used by the species). If there is it could result either from retained chemical cues, or, less likely, some kind of learning.
But I’m having dinner tonight with an expert on caterpillar herbivory, and I’ll try to remember to ask her.
Somewhere in the staff reports section someone asked this question, and someone else reported that a recent experiment had demonstrated that they did retain memory (conditioned behaviour of some kind). You will have to search around for details.
Posts 14 and 16 of this thread are the ones you’re referring to. The original staff report writer says he thinks part of the neural system is preserved, and someone else cites a study that shows butterflies retaining some olfactory conditioning.
