Summary: Aphids are common pests of most indoor and outdoor ornamental plants and vegetables, fruit trees and field crops. Light aphid infestations are usually not harmful to plants, but they can build up tremendous populations in relatively short periods of time and cause leaves to curl, wilt and delay production of flowers and fruit.
A reader asks: I have a bad case of aphids on my tomato plants. What do you suggest I do?
Dear Reader: Aphids are pretty easy to control without pesticides. Tomato plants hold up fairly well against large numbers of aphids. However, severe infestations can cause leaves to curl and may stunt plants. You can usually just wash aphids off the plants with a strong jet of water from a garden hose. Take care to adjust the force of the water so as not to harm the plants. I'd hate to see you defeat the aphids only to find that your efforts have defoliated the tomato plant.
You will have to repeat this effort every few days because large aphid populations will quickly re-infest the plants. You may want to consider ***image1***spraying the aphids with a pesticide while they are on the ground. Be sure your pesticide is specifically labeled for aphids and for treating on or around garden vegetables. Keep in mind that your pesticide treatments will also kill any beneficial insects that are sprayed, so treat only according to the label directions.
Sevin(R) is a common insecticide often used for killing aphids. Remember that aphids can reproduce rapidly, so it might seem like the treatments are not working. Multiple treatments will be required for good control. Try to harvest all ripe fruit before treating.
Before doing any pesticide application I strongly advise getting the insects positively identified by your local County Cooperative Extension Agent or a reputable professional pest control company. No use treating for aphids when you have some other pest.