When the plant is attacked from a herbivor, both of them can produce some volatile organic compounds (VOCs). In a previous study, researchers found that peach leaves in the presence of the green peach aphid began to excrete VOCs. The purpose of our research was to determine whether these substances also affect the movement of aphids. In our study, we explored the chemotactic behavior between synthetic VOCs (methyl salicylate, (E)-β-farnesene, (E)-β-ocimene and (E)-nerolidol) and two-spotted lady beetle larvae (Adalia bipunctata [L.]) and green lacewing larvae (Chrysoperla carnea Stephens). The VOCs that we used in the laboratory study, are typically herbivor-induced compounds from peach cultivars. The first results shows, that all tested compounds have some infuence on both tested organisms. Methyl salicylate, (E)-β-farnesene and (E)-nerolidol showed up as a repellents to two-spotted lady beetle larvae and green lacewing larvae. Otherwise, (E)-β-ocimene were proven as an attractant for both tested organisms. Also the results show us the shortest reactions on VOCs for green lacewing larvae, while two spotted lady beetle larvae was mobile all the time during testing time. In our investigation we used two different concentracions of VOCs. On both tested organisms, the responsiveness were better at lower concentraction but only at first 15 minutes. Later, there were not shown any significant differenties. In the future it will be possible to use capsules with attractants that attract beneficial organisms and thus optimize the use of biological control against insect pests
|
