Synthetic Sugar Ester Controls Whiteflies, Other Pests

Some look-alikes may be better than the real thing. This could be especially true for synthetic forms of a compound made by Nicotiana, a wild relative of tobacco.

Nicotiana leaves manufacture sugar esters that break down the "skin" of a feeding insect, causing the pest to dry up and die. The esters have excellent potential as natural control agents for silverleaf whiteflies and other soft-bodied pests. They are relatively harmless to beneficial, hard-bodied predators like lady beetles.

But extracting the esters from Nicotiana can be difficult and expensive. Synthetic esters have sidestepped these drawbacks.

Gary J. Puterka of the Agricultural Research Service in Kearneysville, W.Va., and Ava Chemical Ventures, Portsmouth, N.H., are working under a cooperative research and development agreement to identify synthetic sugar ester formulations effective in controlling insects.

In field and lab tests, a spray mix of water and synthetic esters controlled pear psylla and other soft-bodied insect pests. Ava is registering a synthetic ester with the U.S. Environmental Protection Agency and the California Department of Food and Agriculture. ARS scientists believe the new ester may be registered as early as 1999.

In addition to pursuing synthetic esters, ARS scientists screened nearly two dozen Nicotiana species to see which ones were the best sources of natural sugar esters to combat pests like the silverleaf whitefly. This insect causes multimillion-dollar crop losses each year to U.S. cotton and many fruits, vegetables and ornamentals.

Whiteflies spend lots of time on the undersides of leaves, shielded from insecticide spray. But the scientists tested a new fogger that the insects can't escape so readily. Details are in the July issue of Agricultural Research magazine. The story also is on the World Wide Web at:

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Scientific Contact: Gary J. Puterka, ARS Appalachian Fruit Research Station, Kearneysville, WV, phone (304) 728-3451, ext. 361, fax (304) 728-2340, email gputerka@asrr.arsusda.gov.