21 September 2008

Oh, frass!

Over at a snail's eye view, Snail says "We should celebrate chewed leaves." Over here, we are celebrating what chewed leaves, in this particular case, chewed tomato leaves, turn into: frass, that is, insect shit.

Yesterday afternoon, I noticed this group of little black pellets on the deck below an overhanging tomato plant.


They turned out to be the frass of 2 tomato hornworms, caterpillars of the five-spotted hawk moth (Manduca quinquemaculata).


And here is the frass end of one of the caterpillars.


The caterpillars have been gorging themselves on the leaves of the tomato plant. That is okay, for the plant has passed its prime, although it still has one little green tomato left, which I am hoping will turn red before it gets too cold.

This time I am also hoping the caterpillars will escape the fate that befell their less fortunate kin last year, braconid wasps. I want to witness them going thru their metamorphosis.


Cindy said...

Hey, I wonder if you could "candle" one of those caterpillars like an egg, and see if there's any wasp larvae wiggling around inside.


Cindy, I was thinking about that too. So I went out with a small but strong flash light & shone it from behind one of the caterpillars. I could see some things inside, but I couldn't tell if those were the caterpillar's organs or larvae.

Anonymous said...

Hi Aydin,

On one trip to Nevis I was handling a big caterpillar and some fresh green frass fell into a dish of water, where, after a while, instead of disintegrating, it floated out into beautiful flat, flower-shaped layers like confetti. I think the outline of the anus of the caterpillar must be symmetrically lobed, and thus the frass is compressed so that the cross-section has an outline like a flower with petals. If you get a chance see if you can get that same effect in water.


Susan H

Anonymous said...

Dear Aydin
I was wondering if you would help me with a snail identification. Do you have an email where I can send you an image or how can I attach one?


Salima, send it to snailstales AT earthlink.net