[Mechanism of cis-8-dodecenyl acetate suppression of male Laspeyresia pomonella codling moth responses to the sex attractant trans-8,10-dodecadienol]. / O mekhanizme podavleniia tsis-8-dodetsenilatsetatom reaktsii na polovoi attraktant trans-8,10-dodekadienol u samtsov iablonnoi plodozhorki Laspeyresia pomonella.

In field experiments, studies have been made on sex attractiopn of males in the moth L. pomonella. Cis-8-dodecenyl acetate (DDA) was confirmed to be a potent inhibitor of male attraction to the traps baited with virgin females or to a synthetic sex attractant (sex pheromone) trans-8,10-dodecadienol (DDD). DDA also slightly reduced the mating activity under laboratory conditions. The inhibitory effect of DDA on male sex attraction was studied by means of electroantennogram technique. Male antennae were stimulated by DDD and DDA either separately or in combination, DDA vapours being superimposed on the constant DDD background. DDD evoked always negative (excitatory) EAGs, but DDA elicited complex EAGs including both negative and positive (excitatory) EAGs, but DDA elicited complex EAGs including both negative and positive waves. Experiments with double stimulation showed that DDD and DDA produce excitation in different groups of the olfactory receptor cells. Besides, DDA was found to inhibit the EAG evoked by DDD. This inhibition is presumably due to hyperpolarization of the DDD-sensitive cells. Both physiological effects may be involved into inhibition of behavioural reactions in males. The inhibitory mechanism based on competition between DDA and DDD molecules for common receptor sites, seems to be lessprobable.