A day late

The billions of periodical cicadas of Brood XIII are expected to launch their invasion of northern Illinois and parts of Iowa, Wisconsin, Michigan, and Indiana this week, actually yesterday. They're late!

Some cicada facts:
• Cicadas are often called locusts, but locusts are migratory grasshoppers that often travel in vast swarms.

• Periodical cicadas are found only in the United States east of the Great Plains. Seventeen-year cicadas are found mainly in the northern, eastern, and western part of their range. Thirteen-year cicadas predominate in the South. Within the 17-year cicadas there are 12 year-classes or broods.

• Only the males sing. The females are lured to the sound and fly nearer.

• In China male cicadas are kept in cages in people's homes so that the homeowners can enjoy the cicadas' songs.

• Cicadas may give away their pending emergence by building thousands of "chimneys" or "stovepipes" on the ground, especially near trees.

• The transparent wings of cicadas are said to filter out ultraviolet light. People who have placed a cicada wing on their skin prior to exposure to the sun have noticed that they do not tan under the wing.

• Male cicadas die soon after mating. Females lay 400 to 600 eggs in as many as 40 to 50 different nests before they die.

• Cicadas are said to make good eating because they are low in fat and high in protein. The best way to eat cicadas is to collect them in the middle of the night as they emerge from their burrows and before their skins harden. When they are in this condition—like softshell crabs—they can be boiled for about a minute. It is said they taste like asparagus or clam-flavored potato. Mmm! Yummy!

• The animal world pigs out on the cicada feast. Particularly, songbirds make good use of the bonanza, and their young are well supplied with the nutritious insects. Moles are said to flourish on the fully grown nymphs in the weeks prior to emergence. Other wild animals that enjoy the advantage include snakes and spiders.

• Cicadas generally leave no lasting damage, except perhaps to young trees and shrubs.

• The remains of cicada bodies may lie so densely on the ground that there is a smell of decay, but the bodies provide good nutrients for the soil.

• Billions of cicada nymphs hatch in their nests high in the trees, drop to the ground, and burrow into the earth. There they find a succulent tree root, which they tap into with a special strawlike mouth part. They feed on the tree sap and pass through their various growth stages until, 17 years later, it is time to emerge and renew their life cycle.