ENVIRONMENTAL FATE OF PYRIPROXYFEN

Abstract

This document reviews the environmental fate and environmental effects for pyriproxyfen 2-[1methyl-2-(4-phen-oxyphenoxy)ethoxy]pyridine (C20H29NO3). Pyriproxyfen is a juvenile hormone analog and a relatively stable aromatic compound. It functions as an insecticide by overloading the hormonal system of the target insect, ultimately affecting egg production, brood care and other social interactions, and inhibiting growth (Glancey et al., 1990). It is active at 25100 grams active ingredient per hectare (Hopkins, 1994). Pyriproxyfen works well against public health insects like houseflies and mosquitoes (The British Crop Protection Council 1991). Pyriproxyfen is reported to have 95% inhibition of emergence for mosquito larvae and its effects on mosquito larvae lasted for two months after application (Miyamoto et al. 1993). Currently, pyriproxifen is one of several insecticides used for the control of the Red Imported Fire Ant (Solenopsis invicta) in California. For managing fire ant, pyriproxyfen is formulated as bait on small particles such as corncob grits. These particles contain the insecticide plus a food attractant, which is usually soybean oil. The ants are attracted to the bait, and they pick it up and carry it back into the mound. At some point, a toxic dose is reached, and the ants begin to die. Baits are used as mound or broadcast treatments over the infested area. Pyriproxyfen is also effective in controlling other insect pests, such as Green Peach Aphid, Arrowhead scale, Greenhouse whitefly, and Pear psylla.