Abstract
In the past two decades, the insect growth regulator (IGR), diflubenzuron, has shown excellent activity against economically important terrestrial insects and is also highly effective against aquatic dipterans, such as Chaoboridae, Chironomidae, and Culicidae, at field rates ranging from 2.5 to 16 ppb. Diflubenzuron, when applied directly to water for control of aquatic dipterans, simultaneously reduces some invertebrate populations for short periods of time. The purpose of this study was to assess adverse effects on invertebrate populations in a pond in Florida located amid citrus trees and receiving air-drifted diflubenzuron from surrounding citrus areas commercially treated for the control of the citrus rust mite. No apparent adverse effects of diflubenzuron on zooplankton and benthic invertebrates were seen in an exposed pond located amid the treatment area. The largest residue of 197 ppt of diflubenzuron in the exposed pond occurred 2-days post-application, with levels returning to trace amounts (< 27 ppt) by day 14 post-application. (VerNooy-PTT)