Those pesky and destructive whiteflies: what's a gardener to do?

If you see a cloud of white insects flying around your vegetable garden, unfortunately this means you have the dreaded whitefly. They are especially attracted to lettuce, and are a huge problem for Arizona lettuce growers in the winter. They also attack tomatoes, peppers, cabbage and the foliage of carrots, and have a liking to herbs like parsley as well. They are a sucking insect, and can kill the plant within a short amount of time. Since they love dry, dusty conditions, the desert is a perfect climate.

They are dreaded because they multiple incredibly fast and are very difficult to control naturally. Although some experts recommend using beneficial insects for a natural control, this method is not particularly successful in the desert environment because conditions are just not that favorable for many beneficial insects to stick around and do any good. You can try sticky traps, which need replacing as they fill up with insects. Barriers such as floating row covers work, provided you get them on before the whitefly sets eggs on your plants, but this does not work once temperatures rise into the mid to upper 80’s because it just plain gets too hot under there.

Since whiteflies love dry, dusty conditions, your best bet is to hose off plants often. If you have one plant they particularly like, it may be worth it to sacrifice that one plant to reduce infestation of the others.