In addition, several molds may grow on this sweet honeydew resulting in a black color on the leaves. Ants are also attracted to the honeydew. A single female whitefly may lay 150 to 300 eggs during her lifetime. During the warm summer months, they can develop from egg to adult in as little as 16 days. A harsh cold winter helps to reduce numbers the following summer, but only a few light frosts might mean a bad problem the next year.
Whiteflies are very difficult to control.
Biological control from parasites and predators is of some benefit, but limited due to the excessive honeydew production. Insecticides help, and the best control seems to come from combinations of several insecticides. Every year some growers try planting warm season vegetables such as green beans, tomatoes, or squash about February 15 in hopes of getting an earlier crop and thus a better price. And three times out of five they lose, and the plants are frosted back and killed. All of the above can result in warmer temperatures of one to several degrees.