Physical Characteristics

Aphids may be green, yellow, brown, red, or black depending on the species and the plants they feed on. A few species appear waxy or woolly. All are small, pear-shaped insects with long legs and antennae. When the weather is warm, many species of aphids can develop from newborn nymph to reproducing adult in 7 to 8 days. Because each adult aphid can produce up to 80 offspring in a matter of a week, aphid populations can increase with great speed.

Aphid

Aphids

Behavior

Aphids are small, soft-bodied insects with long, slender mouth parts, which they use to pierce stems, leaves and other tender plant parts to suck out fluids. They’re often found when the temperature is warm but not hot – from 65 to 80 degrees Fahrenheit. Almost every plant has one or more aphid species that occasionally feeds on it. Large populations of aphids cause curling, yellowing and distortion of leaves and stunting of shoots; aphids also can secrete large quantities of a sticky substance called honeydew, which often turns black with the growth of a sooty mold that is a bane of gardeners. Some aphid species inject a toxin into plants, which further distorts growth. Ants are often associated with aphid populations, especially on trees and shrubs, and often are a tip-off that an aphid infestation is present. If you see large numbers of ants climbing up your tree trunks, check for aphids (or other honeydew-excreting insects) on limbs and leaves above. To protect their honeydew source, ants will ward off many of the aphid’s predators and parasites. Controlling ant populations is a key component of aphid management.

Treatment

Aphids are a garden pest, so that’s where you want to look for them – on plants, especially under the leaves. If there are lady beetles (aka ladybugs), lacewings, syrphid flies or other natural predators present, or if aphids are “mummified” (the result of wasps that lay eggs on aphids that hatch into larvae, which then eat the aphids from the inside) or damaged by fungus, the aphid population may be under control naturally. If ants – which chase off the aphids’ natural predators so they can harvest the honeydew – are present, you can wrap sticky material (e.g., Tanglefoot) around tree trunks to keep the ants from climbing to their little aphid ranch, along with ant baits. Your Clark Pest Control technician will know how to evaluate your aphid problem, and will know precisely how best to handle it for you.

Latin name: Aphidoidea, many genera and species