Polyphemus pupa. . . .

Fri Dec 19 14:00:10 EST 1997

><HTML><PRE>Subject: Polyphemus pupa. . . .
>From: heinzedjak at aol.com (HeinzeDJAK)
>Date: Thu, Dec 18, 1997 22:12 EST
>Message-id: <19971219031200.WAA25273 at ladder02.news.aol.com>
>
>Hello all.
>
>I have been wondering about these questions for awhile.  I thought maybe some
>of you out there might have some answers.
>
>I live in Houston, TX, and I find that in the winter, polyphemus moth cocoons
>are very easy to find after the leaves fall, similar to prometheas.  But,
>upon
>reading the books that I own, I gather that polyphemus larva silking their
>cocoons on to the trees is not such a common phenomena; this makes me wonder.
>.why do the ones in Houston silk them on?  I had the opportunity to go to a
>spot out in the country in Missouri this summer while on vacation.  I brought
>my MV light, and secured a polyphemus female.  She laid about thirty eggs of
>which seven hatched.  None of that seven silked their cocoons on to the twig.
>
>The resulting adults hatched out at a bad time for securing wild males, so I
>mated brother to sister.  Out of that mating, 30 made it to cocooning, and
>none
>silked their cocoons onto the twig.
>
>So I wonder, what stimulates the polyphemus larva that live in Houston to do
>it
>so much more?  I have noticed that you find most cocoons on trees that have
>wider leaves, like Pin Oak and Maple.  Could the leaf size be a factor in
>whether the larva does or doen't?  Or is it just some genetic thing?  Also,
>why
>would it be adventageous for the cocoons in warmer climates to stay up in the
>trees?
>
>Thanks a lot!
>
>Dar Heinze
>
><A HREF="mailto:HeinzeDJAK at aol.com">HeinzeDJAK at aol.com</A>
>
>
>
>
>
>
></PRE></HTML>

Dar:

You ask many interesting questions about the phenomena that you observed which
could only be answered by research.  Hopefully somebody may have done some that
is aware of your question.  Based on your preliminary experiment it may be
genetic and there is a selective force in your area that favors the ones that
show the behaviour you observe.  I guess we could ask why Saturnids usually do
not have functional mouth parts, the question leads more to conjecture than to
answers as that type of research does not provide much incentive from a
monetary standpoint.

The question does remain intriguing however and hopefully someone can answer
it.

Best Wishes

S.