Garden Insects: Aphids

Identification

Also referred to as plant lice, aphids are 1/32 to 1/8 inch long, pear-shaped sucking insects. They are soft-bodied and may or may not have wings. Aphids come in black, green, pink, red, gray and yellow, and some have a wooly, white coating. You can usually find them in clusters on the undersides of young leaves and along tender shoots. They are often in the company of ants, because aphids secrete a sticky substance called honeydew, which ants feed on. Sooty mold also commonly grows on honeydew. Winged forms and male aphids generally appear in the fall. Aphids are found throughout the U.S and Canada.

Favorite Plants

Aphids attack small fruits, vegetables, flowers and fruit trees. Some of their favorites include cabbage, celery, cucumbers, greens, melons, potatoes, tomatoes and roses.

Damage

Aphids stunt and distort leaves, buds and flowers by piercing plant tissues and sucking out valuable sap. Feeding can also spread viral diseases.

Organic Methods of Control:

Cultural or Mechanical

• Remove aphids by spraying plants frequently with a strong jet of water.

• Fall plowing helps kill overwintering eggs.

• Interplant mint, garlic, chives, coriander and anise.

Biological

• Attract or release native predators like ladybug beetles, lacewings, aphid midges or parasitic wasps.

Chemical

• Dust plants heavily with lime or spray them with a lime and water solution.

• Fragile plants can be sprayed with neem or an insecticidal soap made from 1 tbsp. of ivory dish soap (or Murphy's oil soap) and 2 cups of water. This only kills aphids on contact so repeat as necessary. Rinse plant leaves within several hours after application to avoid leaf burn.

• Spray dormant oil on fruit trees in late winter to kill eggs.

About The Author: Description: Cotton Aphids
Citation: Clemson University-USDA Cooperative Extension Slide Series