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Aphids - The Bug Review - University of Illinois Extension

Aphid

aphid

Aphid damage on higbush cranberry

Aphids may be green, black, brown, red, pink, or some other color. These pear-shaped insects are slow moving and range in size from 1/16 to 1/8 inch long. They have conspicuous slender antennae and near the rear end of the abdomen there are two tubes called cornicles. Some may have transparent wings.

Habit

Dense colonies of aphids may be found along stems or on the underside of a leaf. They are drawn to succulent new growth. Several generations may occur and populations can build up quickly.

aphid

Aphids on milkweed

aphid

Spirea aphid on crabapple

Damage

Aphids are sucking insects which draw great quantities of sap, causing leaves and stems to become distorted. This distorted growth may be mistaken as herbicide injury. Some plant sap is excreted as honeydew, which makes the plant sticky. Sidewalks, cars, and patio furniture may become wet with honeydew. A sooty mold often grows in the honeydew and blackens stems, leaves and any other surface. Aphids may transmit plant pathogens.

Control

Non chemical: Wash off aphids with a steady stream of water. Avoid heavy applications of nitrogen fertilizer which can encourage succulent plant growth. Natural predators such as lady beetles and aphis lions feed on aphids but may not always provide adequate control.

Chemical: Contact your local Extension office for current pesticide controls.