Our 6-Legged Visitors and Their Kids

Insects and spiders are found everywhere in the world. More than a million species of insects have been identified, nearly 100,000 of which live in North America. Because of their small size, their activities are often overlooked as we go about our own lives. Our awareness is focused, however, when the leaves of a prized ornamentals suddenly disappear or when a butterfly floats gently overhead to settle on a bright flower.
As gardeners, we tend to classify insects as either “good” or “bad”. Beneficial insects perform such services as pollination, honey production and controlling other insects. Pests cause considerable damage to crops, trees and flowers. Keep in mind, however, that the line between “good” and “bad” is easily blurred. Butterflies are beneficial not only for their beauty, but also feed on nectar, aiding in pollination. In their caterpillar stage, however, they are voracious eaters and will strip the leaves from plants. On the other hand, wasps and yellow jackets, unwelcome guests at the cookout, also drink nectar, participating in the pollination process as well.

Beneficials

Honey Bees

Pollinate crops and flowers and produce honey. Numbers have been decreasing because of two parasitic mites. Highly susceptible to insecticides such as diazinon, lindane, malathion, Orthene and Sevin.

Ladybug Beetles
Easily recognized by their rounded, usually spotted bodies. Both adult and larvae feed on scale and aphids, making ladybugs important beneficial predators. Do not bite, sting, carry diseases; do not infest food, clothing or wood and do not breed in buildings.Pests

White Grubs

Larval stage of the Japanese Beetle (a serious pest itself which damages more than 200 plants). Feed on grass, vegetable and nursery plant roots and tend to affect the same areas from year to year.

Fall Webworm

Caterpillars are yellowish green with black spots and long white hairs. Feed on a wide range of deciduous trees including black walnut, persimmon, flowering fruit trees, oaks and maple. Best control strategy is to look for webs after the 4th of July and cut the webs out before they cover large areas of the tree.

Praying Mantis

Would you call this insect “good” or “bad”? A large (2-21/2″) insect hailed as a beneficial predator. However, mantids are cannibalistic, feeding on other mantids as well as caterpillars, flies, butterflies, bees and moths.

Sources: National Audubon Society Field Guide to North American Insects & Spiders Purdue University Plant & Pest Diagnostic Laboratory