Transfer of Chlorfenapyr Among Workers of Reticulitennes W p e s ( Isoptera : Rhinotermitidae ) in the Laboratory

The potential for transfer of chlorfenapyr among subterranean termites was investigated using a donor-recipient (5:95 ratio) experiment. In one experiment, workers of Reticulitenm jkoipes (Kollar) (Isoptera: Rhinotermitidae) were exposed to treated sand at 0,50,100,250, and 500 ppm chlorfenapyr (wt [AI] /wt sand). Exposed workers were allowed to interact with untreated nestmates for 14 d, after which mortality was assessed. The three colonies responded differently to the treatments in this experiment. For two colonies, donor exposure rates of 500 ppm (as well as 250 ppin for colony B) chlorfenapyr resulted in significantly greater recipient mortality than controls. For colony C, donor chlorfenapyr exposure did not significantly influence recipient mortality. In a second experiment examining donor mortality over time, donor tennites exposed to a11 test concentrations of chlorfenapyr (except for 0 ppm) suffered 100% mortality within 5 d. Analysis of donor termite body washes using gas chromatography indicated a linear uptake of chlorfenapyr by termites over the concentration range studied. Thus, for this concentration range, no upper limit (saturation plateau) of temGte uptake for chlorfenapyr was reached.