Timothy Schmidt, age 9, of Staten Island, N.Y., for his question:

WHERE DO TOMATO BUGS COME FROM?

Our precious tomato plants may be attacked by several different insect enemies. But the worst of them is a monstrous green caterpillar  who may grow bigger than your finger. This critter is an insect, so naturally he started life as an egg. The story begins in the dead of night, when a female moth flies around the tomato plants. She has a fat furry body, and her color is mainly brownish gray. Her wings are three or four inches wide and may have a few patches of pale pink or yellow.

She is a sphynx moth, and she chooses a tomato plant on which to lay her eggs because when the caterpillars hatch they like to feed on tomato leaves.    The hungry critters start out too small to notice. They soon grow big and fat, but their green color matches the leaves and they may be hard to find. Search for a twig that has been , stripped of its leaves and most likely you will find the greedy grub right near the scene of the crime.