Hairy moths

[David R. Britton]

In article <199708141338.JAA22186 at comet.connix.com>, jhimmel at CONNIX.COM wrote:

I think that hairs, or long hair-like scales often act as deterrents or
escape mechanisms for moths and butterflies.  If you have ever tried to
hold a struggling large noctuid moth you will know how slippery they can
be (imagine one eluding a birds bill).  At the invertebrate level, I have
often watched large ants trying to make off with a moth, only to end up
with mandibles stuffed full of scales.  Many of the lycaenid butterflies
which pupate in ant nests are partcularly "hairy"; these scales act to gum
up the mandibles of the ants as the adult butterflies emerge from the
nest.  This is certainly the case for Liphyra brassicolis (spelling), and
probably for some of the thecline lycaenids in Australia.

In regards to temperature regulation, heat retention would only apply to
either active insects, or to basking insects (Inactive insects do not
produce heat, being cold-blooded).  Inactive overwintering species would
lose all heat in their body in less than an hour even with the finest
insulating hairs.  Noctuid moths and other stout-bodied species maintain
quite high thoracic temperatures when flying, and the hairy bodies in
these species no doubt increase heat-rentention in the active moth; other
species such as geometrids work at much lower temperatures, and are
correspodingly less hairy.

Hairs, or hairy scales may be important in overwintering species in regard
to controlling water balance by preventing soaking, or preventing water
loss.  Anyone seen any literature on this?

Dave B.

> In the second broods of Mourning Cloaks and some other butterflies that
> overwinter as adults, their bodies have long tufts of hair-like scales
> presumably to help keep them from getting too cold while they wait out the
> colder season under a loose piece of bark or shingle.  Because most
moths fly at
> a time when there is less heat, might their "hairy" bodies help a species
that
> can't count on the sun retain a bit more warmth for a variety of its needs?
>

--
David R. Britton, Biological Sciences, University of Wollongong
Wollongong, NSW, Australia, 2522.
Ph.(61-42) 21 3436,Fax.(61-42) 21 4135