frass expulsion

[Liz Day]

 >As for the projectile frass thing, could it be that the caterpillars
 >simply want to get the frass of the leaves they're on?  Big caterpillars
 >would have no problem with this as their frass is heavy and drops
 >easily, where as small caterpillars' frass does not.

It could be.   It seems the few kinds of larvae I've watched, they either 
shoot the frass or they don't, from the time they're tiny until they're 
large.   As we talk about this, and the advantages of making sure your 
frass doesn't fall to rest on a nearby leaf, I'm wondering why ALL larvae 
don't shoot it out.   Saturniids just let it fall.    Even if you are 
hanging on the underside of a leaf, it might come to rest on the leaf below 
you.  And they have plenty of parasitoids.   Mysterious.

Liz

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Liz Day
Indianapolis, Indiana, central USA  (40 N, ~86 W)
Home of budgerigar Tweeter and the beautiful pink inchworm (Eupithecia 
miserulata).
USDA zone 5b.  Winters ~20F, summers ~85F.  Formerly temperate deciduous 
forest.
daylight at kiva.net
www.kiva.net/~daylight
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