Cell responding to pheromone components and plant volatiles could affect semiochemical based control strategies of insect pests in agicultural ecosystems

Electrophysiological and behavioural responses by several insect pests have been recently recorded in order to identify plant volatile compounds, and particularly kairomones, involved in the host-finding process and oviposition site selection. Such compounds have been addressed as candidates to be used in semiochemical based control strategies since they are potentially able either to enhance the sex pheromone activity or to monitor female emergence or to interfere on their behaviour. During similar studies, olfactory cells sensitive both to pheromone components and plant volatiles in Cydia pomonella antennae were described. In the present paper we analysed single cell recordings (SCR, surface contact technique) from olfactory neurons of different tortricid moths (C. pomonella, C. splendana, C. fagiglandana, Pammene fasciana, Lobesia botrana) stimulated by the two categories of compounds. Cellular types varying from the specific (relatively to the tested compounds) to the highly generalist ones were identified. The finding of these cells partly supports the observations reported by various authors about the ability of plant compounds to modulate the biological activity of a pheromone component. It seems not inappropriate to hypothesize that these “peripheral interferences” in odour perception could culminate in changeable behavioural responses that should also be of practical importance when pheromone based control strategies are applied in different agricultural environments, where they frequently show a variable efficiency.