Figure 2. Gramine toxicity to brown planthoppers (BPHs).

BPHs were fed on artificial liquid diets containing the indicated concentrations of gramine. At 24, 48, 72 and 96 hrs post feeding (h.p.f.), the BPH mortality was determined. Data represent the means ± SD from three independent experiments with triplicate glass tubes (at least 10 nymphs in each tube) examined for each treatment. Different letters on the bars indicate significance at P<0.05.