Figure 3: Test of attractiveness of plant-derived moth pheromones.

Trap catches of males of two small ermine moth species obtained with synthetic pheromone (positive control), plant-derived pheromone and blank traps (negative control) (N=5). Plant-derived pheromones were prepared by acetylation of corresponding alcohols produced from the 14C and 16C treatment, respectively. The treatment producing 14C compounds was used alone for trapping Yponomeuta evonymella, and a mixture of the two treatments producing 14C and 16C compounds was used for trapping Y. padella. The synthetic baits for Y. evonymella contained 14:OAc/E11-14:OAc/Z11-14:OAc in a blend ratio of 187:45:100, and the synthetic baits for Y. padella contained 14:OAc/E11-14:OAc/Z11-14:OAc/Z11-16:OAc in a ratio of 187:45:100:400. The baits of plant-derived compounds contained above-mentioned acetates and minor by-products. Moth catches were species specific with both synthetic and plant-derived pheromone. In the case of Y. evonymella, the plant-derived pheromone was not as effective as the synthetic pheromones (t-test, P=0.012), whereas for trapping of Y. padella, the plant-derived pheromones showed no difference from the synthetic pheromones (t-test, P=0.896). The blank control traps did not catch any moths. Error bars represent s.e.m. (standard error of mean). NS, not significant; *, significant (P<0.05).