Aphids

Family Aphididae

HOST Several hosts

DAMAGE/SYMPTOMS Aphids are sap-sucking insects and the saliva they release from feeding can cause discoloring, curling, distortion, or overall lack of vigor.

LIFE CYCLE The aphid life cycle varies significantly between species. In general, aphids overwinter in the egg stage on a host and reproduce in large numbers asexually during the growing season. Later in the summer, most aphids produce winged generations and move to a second host. In the fall, they return to their primary host, mate, and lay eggs.

MANAGEMENT A strong spray of water alone can effectively remove aphids. Aphid populations tend to be higher in plants that are fertilized liberally with nitrogen, as this produces flushes of succulent growth. Avoid excessive watering and use slow-release fertilizers. Placing cardboard wraps around the tree that are covered with a sticky substance, such as Tanglefoot, can prevent ants from climbing. Ants have a mutualistic relationship with aphids; they hoard the honeydew released from aphids and then defend the aphids from their natural enemies in return. There are a variety of lower toxicity contact products available including soaps, oils, and botanicals. Good coverage with contact pesticides is essential. Systemic insecticides are particularly useful when contact is difficult and to protect new growth over time (active ingredients such as imidacloprid and dinotefuran).

A Rose aphids. B Green peach aphid. C Black cherry aphids.