Fig. 2. The proportion of H. virescens females (A) and males (B) that showed the PER 1 h after conditioning experiments using 100 mg racemic linalool associated with a sucrose reward at five different ISIs (-1, 0, 1, 2 and 3 s). The interval of 1 s gave the best performance with 44% of the females and 36% of the males responding to the odorant. The groups differing significantly from each other (Fisher's exact test with Bonferroni correction; P<0.005) are marked with `a' vs `b'. The number of insects in each group is given within the bars.