Aphids - Vegetables

Life cycle/habits

• Eggs laid in fall overwinter and hatch in spring. 
• Many more generations are produced during the growing season. 
• Aphids move slowly, congregating on new succulent growing tips and leaf undersides.
• Winged dispersing adults may fly to other plants.
• Aphids have long slender mouthparts to suck plant sap and excrete sticky honeydew. 
• Aphids feed on plant leaves, stems or roots, depending on the species, and can transmit plant diseases.

Host plants 

• A wide range including beans, beets, broccoli, Brussels sprouts, cabbage, cantaloupes, cauliflower, collards, cucumbers, eggplant, kale, peppers, potatoes, pumpkins, radishes, spinach, squash, tomatoes, turnips, watermelons.

Signs and symptoms 

• Sucking of sap stunts plants. Leaves curl and/or discolor with white or yellow stippling.
• Sooty mold may grow on honeydew, blackening leaves.
• Aphids congregate on new growing tips but are also attracted to lush, overly fertilized growth or stressed plants.

Monitoring

• Examine transplants to intercept infested plants.
• Check leaf tips and undersides and along stems for clusters.
• Inspect for sooty mold growing on honeydew. Note any curling, stunting, or stippling.
• Ants frequently harvest honeydew from aphids, so the presence of ants may be a sign of aphid infestation.

Prevention/control

• Do not plant infested transplants.
• Aphids are mainly a problem May through June but have many natural enemies (e.g. ladybird beetles, lacewings, syrphid fly, parasitic wasps) that keep numbers controlled. Look for brown, swollen parasitized bodies.
• Encourage predators with attractant plants and avoid toxic pesticides.
• Control low aphid infestations with a robust spray of water.
• If damage is obvious and predators and parasitoids few, use insecticidal soap. Check product label for directions before spraying. And avoid spraying when temperatures are above 85 degrees F.