Nothing can ruin a good day in the garden like a plant overrun with pests. How you deal with the problem depends on what has invaded your yard. Here are common garden pest control methods for a wide range of insects.
What they look like: Pear-shape and soft-bodied, aphids can either be winged or wingless; a white cottony form also attacks fruit trees.
Plant damage: Aphids are typically found clustering on the growing tips of stems, where they suck sap, distort leaves and flowers, and spread plant viruses. In addition, aphids secrete clear, sticky honeydew, which attracts ants.
Pest control method: Ladybugs and other beneficial insects typically bring aphids under control. In addition, a strong spray of water from a hose can knock them off plants. Insecticidal soap works, too.
Learn more about aphids.
What they look like: Caterpillars and worms are the larval stage of moths and butterflies, which makes them trickier to deal with because many will turn into beautiful butterflies.
Plant damage: Caterpillars and worms will feed on plants, chewing holes in leaves and stems.
Pest control method: Larvae that develop into butterflies are a nuisance, but since butterflies themselves generally don't damage plants, they can be left alone or picked off if necessary. Caterpillars can be controlled in several different ways. Natural predators such as birds might help; install a birdbath to draw winged visitors to the garden. Parasites such as some tiny wasps might also decrease the caterpillar and worm population. (Look for small white eggs on the backs of caterpillars as evidence of success.) Discourage moths from laying eggs by using floating row covers over plants, but make sure to remove row covers when food plants need to be pollinated. Biological material Bt (Bacillus thuringiensis) is a garden pest control method that is harmless to people, animals, and beneficial insects. Or pyrethrin, a botanical contact insecticide, can be used; follow package instructions.
Learn more about cabbage loopers.
Learn more about fall webworms.
What they look like: Earwigs hide during the day in crevices and under garden debris, so you'll have to look at night for their distinctive bodies: They are 3/4 of an inch long and have pincers at the rear end of their bodies.
Plant damage: Watch for holes in leaves, stems, flowers, and fruit.
Pest control method: Lay pieces of cardboard on the soil overnight; in the morning, collect and dispose of the insects. Or spray them with an over-the-counter pesticide. Insect bait pellets can also be scattered on the ground.
What they look like: Metallic blue or green, Japanese beetles are 1/2-inch long and have coppery wings.
Plant damage: Japanese beetles are voracious eaters: They consume leaves and flowers, leaving behind only leaf veins. Common targets include roses and hibiscus. Grubs of Japanese beetles are also a problem; after overwintering in the soil, they emerge in spring to eat grass roots.
Pest control method: Handpick Japanese beetles and dispose of them in a container of soap water. Spread beneficial nematodes (Heterorhabditis bacteriophora) over lawns in early spring. To control adults, spray a botanical insecticide such as neem or a synthetic pesticide containing malathion or carbaryl. Beetle traps can also be used, but place them far from susceptible plants.
Learn more about Japanese beetles.
What they look like: Mealybugs are small, sap-sucking, cottony insects.
Plant damage: Mealybugs secrete as they eat, which can lead to plant diseases as well as sooty mold and ants.
Pest control method: In the garden, grow small-flower nectar plants, such as sweet alyssum and Scabiosa; this will attract natural predators including ladybugs, mealybug destroyers, and green lacewing larvae. Insecticidal soap, summer oil, neem, or an insecticide with carbaryl can also help control mealybugs.
Continued on page 2: Scale Insects, Slugs & Snails, and Tent Caterpillars