On Fri, 02 Apr 2004 12:24:43 GMT, Bill McKee
wrote:

I know that the gentle rain falling from my oak trees lately is
catepillar castings. But why are they "wasting" all of that good silk
in those long threads hanging down, snagging the oak tassles?

It's a survival strategy. Whenever there is some sort of disturbance,
they immediately drop on those long threads. I think the silk is
recycled as they climb up, but there is bound to be some energy loss.

Also, it would seem to make them more vulnerable to predators, but I
have never seen a bird take a caterpillar that way. Perhaps the birds
that eat caterpillars can't get around the idea of catching them out
of the air and the birds that eat flying insects don't recognize them
as food. Grackles are smart enough to figure out that dog food softens
in water, maybe some genius grackle will discover caterpillars on a
string.

Anyway, give an oak tree limb a good shake this time of year and you
will dozens of the critters come cascading down.

I went for my usual walk in Dick Nichols park yesterday, not thinking,
and must have picked up 20 or 30 of the things in my hair and down my
back. I had to wave my cane in front of me as I walked. All evening
long I was picking caterpillars.

Elliot Richmond
Freelance Science Writer and Editor