Issue: August 9, 2008

Caterpillar invasion
Can I eat peaches after accidental pesticide application?


I'm trying to locate information on a caterpillar invasion out here in Talavera (a housing development east of Las Cruces near the base of the Organ Mountains). Do you by chance know anything about these caterpillars? They are here in droves.

Regina G.


Dr. Carol Sutherland, NMSU Extension Entomologist, received this question and shared it so others in New Mexico would have the benefit of this information.

In her answer to this question, Dr. Sutherland stated that this is currently a hot topic in Southern New Mexico. She explained, "When monsoon started this year, the rains just kept coming at the right intervals. Seed in the soil bank sprouted providing food for the caterpillars and the little worms had a real buffet. They probably succeeded better than any natural enemies and now, about 5-6 weeks after hatching, they are ready to move on. The hordes are mature caterpillars leaving their pasture, looking for whatever is right to stimulate pupation. Sometimes the hordes can get so dense that they cross roadways, making them slick as cars squash them."

She identified the caterpillars in this case as "the mature and nearly mature larvae of the white-lined sphinx moth, Hyles lineata." The larvae have been feeding on native evening primrose plants and related weedy native range plants, doing little permanent damage to the wildflowers or to landscapes and gardens. The adult form of the white-lined sphinx moth is a large dark brown moth with pointed forewings that is often seen at dusk sipping nectar from flowers. These moths are often mistaken for hummingbirds because both are similar in size, both can hover and both are easily heard humming as they visit flowers.


On Sunday, July 27th, I inadvertently applied a chemical under our peach tree which has peaches ripening. I used 2 ounces of a product mixed with a pint of water. I need to know if the peaches will be safe for us to eat. The product I applied contained tebuconazole, imidacloprid, and inert ingredients.

Johnny J. A.


The product you used stated on its label that it was not to be used on edible crops. As a result, I cannot tell you it is safe to eat the peaches. Even though this was an accidental application, the result is still the same. You cannot harvest and eat the peaches. Both you as the user and I as the advisor are bound by the instructions on the label which carry the force of law. The label states that "It is a violation of federal law to use this product in a manner inconsistent with label directions." The product has not been tested and approved for use in this manner.

I called the manufacturer of this product who gave me the following information: "we need to make it clear to all users of Bayer Advanced All in One Rose & Flower Care that it is not permitted to be used on peach trees whose fruit is to be consumed. Bayer Advanced recommends that the fruit must not be used for human consumption this year (it can be destroyed or composted). Also, as to next year (2009), there is no concern with any significant residues in the peaches (treated in 2008( and the peaches produced on these trees can be consumed."

Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, email:, office: 505-865-7340, ext. 113.


For more gardening information, visit the NMSU Extension Horticulture page at Desert Blooms and the NMSU Horticulture Publications page.

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