11 March 2011

Simroth's snail-imitating moth

Heinrich Simroth was a German malacologist of some distinction. Once he published a short paper* about the larva of a coleophorid moth whose case he thought resembled the shell of a clausiliid snail.

Here are Simroth's drawings of the moth larva.

According to BugGuide, coleophorid larvae from the second instar onward carry a "portable case" around them, which they make using silk and/or plant material.

Simroth also thought that the larva's mimicry protected it from predatory birds: "I think it is clear that the whole arrangement is very effective and likely to deceive small birds frequenting the rocks for feeding upon insects."

Simroth did not identify the moth. I don't know if anything more substantial on the presumed mimicry of these moths has since been written.

*Simroth, H. 1901. Clausilia mimicked by a microlepidopteron. Journal of Malacology 8:33-34.


Anonymous said...

Well the one illustrated did apparently look a little like Clausilia, but I would like to see a whole lot more looking the same before saying yes to the idea of mimicry.

Also I would like to know at what angle the larva carries the case, and so on. I mean, a lot of birds are pretty smart. Actually most animals are pretty smart when it comes to spotting food items; I think in many examples mimicry has to be fairly convincing to fool a predator.

Susan J. Hewitt

John said...

I'm not sure which species Simroth studied, but some of the moths in the Coleophoridae are known to build and carry cases when they're larvae. One of them, the Pistol Casebearer has a case that looks at least somewhat snail-like, though it doesn't match Clausilia.