luna foodplants

[Martha V. Lutz & Charles T. Lutz]

Someone wrote:

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To: leps-l at lists.yale.edu
Date: Sun, 06 Jun 1999 00:06:58 GMT
From: oli at oli.net (oli)
Sender: owner-leps-l at lists.yale.edu
Subject: Luna foodplants
Reply-To: oli at oli.net
X-Sender: newsgate at newsguy.com

is there anything evergreen that A.luna will feed willingly on?
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Sorry to respond to the whole list, but my attempt to respond only to the
sender bounced right back.  Here is my input.

Most Saturniid larvae will feed 'willingly' on almost anything--if you
starve them long
enough first!  In which case they often have trouble molting and may die
from either starvation, failure to complete a molt, or from effects of the
plant.  Mine will eat Ginkgo biloba, but they are not happy about it and it
ultimately kills them.  Ditto for a fern (Matteucia struthiopteris, I
believe it is).  Samia cynthia ricini larvae will eat leaves and petals of
Campsis radicans, as well as fern fronds, Ginkgo leaves, and assorted other
plants.  Within about 3-6 hours, even some classically 'monophagous' lep
larvae (including Danaus) will overcome their inhibitions and eat almost
any plant species offered.  What does this say about the mechanisms that
control feeding behavior?  Their central wiring, I mean!

Also, what does this say about Danaus plexippus larvae that have no
alternative but pollen-dusted leaves?  For four days!  I seriously question
whether they would even eat such leaves in the field, or whether they would
simply crawl down to cleaner leaves lower on the plant and eat away happily
and safely . . . without any pollen, Bt toxin-filled or otherwise!   Did
anyone do any field work before starting the lab studies, to see if larvae
ever eat 'pollinated' leaves under normal conditions?  As a Cornell alum
(B.S. in entomology) I feel quite comfortable wondering whether the lab
study done there has any relevance to the real world, with regard to the
fate of Monarch buterflies.  (I am not questioning the toxic properties of
Bt corn, or even its pollen . . . just the validity of starving lep larvae
until they eat weird things like pollen, and then using that data to draw a
conclusion about ecological consequences.)



Martha Lutz
lutzrun at avalon.net