frass expulsion

[Ron Gatrelle]

Xi Wang wrote:
> Monarchs are toxic, so would it not make sense for the eggs, and hence
> newly emerged larvae, to be just as toxic, if not more?
>


Not all monarchs are "toxic".  Some milkweeds are more so and others less
toxic or not at all -  I do not remember which. I seem to remember that
Butterfly Weed ( A. tuberosa) is non? The "protection" is achieved for
monarch adults and their mimics (which are not irritable to predators)
simply by the high percentages of distasteful ones producing a memory
aversion to the red wing pattern. In the egg and larval stages I would
think there is a whole different set of factors.

As I said in my previous post here (which I assume went through), anal
frass projection is an automatic mechanical reflex action produced by
structures in the anus of some species. Many other larva of many varied
genera remove excreted frass from their proximity orally.  It is picked up
with the mandibles and flung or dropped away from their site. Wasps and
flies in particular hone in on the sent of the frass to locate prey.  It is
also know that various larva are able to "hear" (detect) certain "humm"
frequencies which are at those generated by specific wasp predators.

This is the type  of interesting and useful info found in scientific
publications and why lepidopterists have thus traditionally subscribed to
things like the Journal of the Lepidopterists' Society etc.

It remains disappointing to me that either 1) those on this list with
answers to these questions based on detailed research are not posting, or
2) that those types of people are not subscribed.
Ron


 
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