Working the Bugs Out

Slugs/Snails
Description: Soft-bodied, legless soil dwellers with shells (snails) or without shells (slugs)
Where: Found in moist, shady areas throughout North America. Hostas and fruits are favorite plants
Damage: Chew holes in leaves; leave slime trails
Controls: Use drip irrigation to keep garden drier. Also try Sluggo and Escar-go baits, copper barriers around individual plants, diatomaceous earth, saucers of beer and trap boards. Toads, snakes, ducks and geese feed on slugs

Lawn Grubs
Description: May/June beetle adult is reddish brown to black with hard shell; Southern masked chafer adult is light brown; Northern masked chafer adult is chestnut brown. Larvae of all are 1-inch long, white, C-shaped grubs
Where: May/June beetle found throughout North America. Southern masked chafer in Midwest and Southeast. Northern masked chafer in Northeast. Larvae live in soil under turfgrass
Damage: Adults of May/June beetle chew foliage of oak, willow, apple, poplar and birch trees. Most damage from larvae comes from their chewing on grass roots; turf turns brown from lack of roots in summer
Controls: Predatory nematodes (Steinernema and Heterorhabditis, Grub Guard, Grub-Away) mixed with water and applied to soil

Spider Mites
Description: Reddish-brown or pale, tiny, eight-legged. Often produce webbing more visible than the mites themselves
Where: In dry areas throughout North America. Common in warm locations; most often on leaf underside. Roses, beans and marigolds are favorites
Damage: Suck plant juices from leaves. Create silvery stippling on leaf; leaves yellow and brown; webbing
Controls: Forceful water spray, insecticidal soap, horticultural oil, lacewings, ladybugs, predatory mites (Galandromus, Phytoseiulus), neem, sulfur dust.

Gypsy Moth
Description: Adult female is a creamy white moth; male brownish moth. Larvae are black hairy caterpillars with five pairs of blue spots and six pairs of red spots on back. Egg masses are buff-colored
Where: Throughout Northeastern U.S.; isolated elsewhere. Egg cases are laid everywhere. Larvae feed on the foliage of shade trees
Damage: They defoliate trees by chewing leaves; oaks are a favorite
Controls: Handpick and destroy egg masses; spray B.t. when larvae are young

Japanese Beetle
Description: Adults are metallic green with coppery wing covers; larvae are grayish-white grub
Where: Concentrated in eastern third of U.S.; less common elsewhere. Adults feed on foliage of more than 300 species of trees, shrubs and flowers; larvae in soil
Damage: Adults chew leaves and flowers of plants; larvae feed on roots
Controls: For larvae: Milky Spore or nematodes (Grub Guard, Grub-Away). For adults: neem or rotenone; place Japanese beetle pheromone traps outside garden, not near plants attractive to the beetle

Grasshoppers
Description: Green, brown or reddish yellow with enlarged hind legs for jumping
Where: Throughout North America; most common in dry areas. They prefer vegetables and flowers, though they might eat most any plant
Damage: All stages chew leaves and stems of many kinds of plants. They feed during the day
Controls: Keep garden watered well. Hot Pepper Wax discourages feeding; Nolo Bait, a protozoan that kills only grasshoppers, is effective if applied over at least several acres early in they year. Guinea hens and turkeys eat grasshoppers

A forceful spray of water knocks pest like aphiuds and spider mites off plants, and they won't find their way back. Spray plants routinely.

Place a stiff paper collar around young seedlings to prevent cutworms from chewing through the stem, which kills the plant.

Thousands of eggs of the trichogramma wasp are attached to this card, which is placed in the garden. Hatched wasps destroy the eggs of plant-eating caterpillars.

Millions of microscopic beneficial nematodes are attached to this blue sponge. Swishing the sponge in water releases the live nematodes, which are then sprayed on the lawn to seek out and kill grubs.

If you think the only good bug is a dead bug, think again. Many of the insects in our midst are beneficial—the natural enemies of insects that feed on plants.

Ladybugs are beneficial both as winged adults and soft-bodied larvae, feeding primarily on aphids, as shown below. They also feed on mites, scales, and mealybugs.

Beneficial bug:

White cocoons of a parasitic wasp stick to the back of a tomato hornworm. Each cocoon produces a wasp that will seek out another hornworm to attach to.

Beneficial bug:

An adult parasitic wasp emerges from an "aphid mummy" (below) after developing from an egg laid inside the living aphid.

Beneficial bug:

Adult green lacewings eat only nectar, pollen, and aphid honeydew, but the alligator-shaped larvae are extremely voracious predators that suck the body fluids from prey. Below, an impaled aphid is the victim.