‘No Quick Fix’ Seen in Battling Growing Swarms of Ash Whiteflies

Agriculture officials and entomologists said Friday that there is “no quick fix” to countering the growing swarms of ash whiteflies in Orange County and other parts of Southern California, but the pesky insects could eventually be controlled through predators and parasites.

During a meeting of the California Agricultural Commissioners and Sealers Assn. subcommittee on the ash whitefly in Anaheim, Orange County Agricultural Commissioner James D. Harnett urged tormented homeowners not to spray pesticides in an attempt to kill the flies that have recently infested their trees.

“It doesn’t work very well and it’s not a good idea,” Harnett told reporters after the meeting Friday. “There is no quick fix. It is a matter of controlling the flies, not eradication.”

Harnett said he understands why residents in Southern California are upset with the infestation of the flying insect, which is about the size of the head of a pin. The flies are so numerous in places that people can no longer hold gatherings in their back yards, Harnett said.

Reduction Expected

But, he added, the ash whitefly will never be eradicated completely, and residents should get used to it. Harnett said that when control programs are under way the number of the flies will be reduced considerably.

The fly hangs on the underside of the leaves of ash trees and ornamental pear trees. There it eats the leaves and lays its eggs. Although the insect was spotted for the first time only last year, Harnett said September and October seem to be the worst months for the ash whitefly.

Thomas Bellows, UC Riverside associate professor of entomology, said officials are studying predators and parasites that are successfully used in Europe and Israel to control the ash whitefly.

One of the predators, similar to the orange lady bug but small and bronze colored, eats the ash whitefly.

By the middle of next year, Bellows said he hoped to be ready to release whatever predators or parasites that will control the pest and yet not pose a danger to the environment.

Meanwhile, Bellows advised residents to keep the trees that the whiteflies infest well watered and be prepared for the leaves to drop off a little sooner than usual.