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 other surfaces. Aphids attack a wide variety of plants; most species feed on one or a few species of closely related plants.

aphids on begonia

aphids on lettuce

aphids on iris

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. Dense colonies of aphids may be found along stems, in and around the roots, or on the underside of a leaf. Several generations may occur and populations can build up quickly.

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Identification and Control Information

Species Specific Resources & Deeper Reading

More Information

[Photos, left to right: Jim Baker, North Carolina State University, Bugwood.org; Whitney Cranshaw, Colorado State University, Bugwood.org; Whitney Cranshaw, Colorado State University, Bugwood.org]