Whiteflies and Basil Plants

Adult whiteflies don't feed at all. It is their tiny offspring, which are called nymphs, which feed on the undersides of basil leaves and damage crops.

Damage

• Female whiteflies lay their eggs on basil plants and the nymphs begin to feed as soon as they hatch. Feeding nymphs weaken the plant and cause leaves to turn yellow and drop off.

Transplants

• Whiteflies are serious problems in greenhouses. Many whiteflies found in the garden were brought home on greenhouse-grown plants purchased at garden centers and nurseries. Before purchasing basil plants, give them a little shake and watch for a swarm of tiny adult whiteflies. Check the undersides of leaves where nymphs like to hide.

Mechanical Controls

• Use a hand-held vacuum cleaner to suck up adult whiteflies. Use row covers when setting out plants if you are sure your transplants aren't already infested with whiteflies. Yellow sticky traps reduce the numbers of adults. Remove and destroy infested crop debris.

Insecticides

• Both insecticidal soaps and sprays containing neem oil are effective against whiteflies on basil plants. These insecticides must come in contact with the insects. Neem oil not only kills the nymphs, but also deters female whiteflies from laying eggs on the plants.