Fig. 2.

Effects of four detoxification enzyme inhibitors (i.e., insecticide synergists) on fipronil toxicity in B. germanica adult males. Each enzyme inhibitor (piperonyl butoxide [PBO], S,S,S-tributyl phosphorotrithioate [DEF], diethyl maleate [DEM], and triphenyl phosphate [TPP]) was topically applied in 1 µl acetone 1 h prior to application of a population-specific LD₅₀ (shown below the population name). Percent mortality was determined 4 d after treatment and mortality was corrected for control mortality (synergist only). The mean shown is of 3 replicates with 10 males each (n = 30 males per treatment). Significant differences between fipronil-only treatments and fipronil plus inhibitor treatments were determined using Chi-square analysis, with significance indicated by * (P < 0.05).