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Posted 19 February 2007. PMN Crop News.

Some Like It Hot, But Not These Pests

University of Maryland Cooperative Extension.

College Park, Maryland (February 8, 2007)--Imagine using a hot water treatment to “cook” aphids, mealybugs, scale, thrips, and spider mites instead of spraying them with pesticides. A University of Maryland Cooperative Extension team has collaborated with a colleague in Hawaii who’s developed a way for treating tropical plants. Team leader Stanton Gill directed experiments in Maryland to find threshold temperatures for temperate-zone plant material. “There’s a small temperature window,” Gill says, “at which insect pests die and plant material is tolerant.” Most plants, he says, can tolerate between 120°F and 125°F for varying amounts of time.


The goal, says Gill, specialist in Integrated Pest Management (IPM) for nurseries and greenhouses, was to devise a portable hot water immersion system for treating plant cuttings while insect pests are propagating. The system needed to be economical and relatively easy for nursery plant growers to build and operate. Aiding Gill, who works at the Central Maryland Research and Education Center, Ellicott City, were ag engineer David Ross, commercial horticulture specialists Chuck Schuster and Ginny Rosenkranz, IPM specialist Paula Shrewsbury, and ag technician Suzanne Klick. More details appear in "Keeping the Heat on Pests" (PDF), which appeared January 1 on the American Nurseryman web site.

Ginny Gerhart