Matt Anderson, age 11, of Cleveland, Ohio, for his question:

WHAT IS A LEAF MINER?

A leaf miner is a tiny fly, moth or beetle which, in the larva stage, lives between the upper and lower skins of leaves. Leaf miners eat the inside of the leaf, leaving white winding tunnels or broad whitish blotches.

Leaf miner larva of some species mine under the skin of fruits, stems or branches of shrubs and trees. These larvae can be highly destructive.

The lives of leaf miners begin when the female insects lay small eggs on the undersides of plant leaves. From the eggs are hatched larvae that begin to eat tunnels, or mines, in the leaf.

There may be one or more larvae in a leaf and some migrate from leaf to leaf. They may become full grown in one to three weeks and then they enter the pupal stage of their lives. Some drop to the ground to make cocoons and others stay on the inside of the leaf until they develop into adult insects.

Three or four generations of leaf miners may appear in one season. They are found throughout the world. There are many species.