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.
