Electrophysiological and field activity of halogenated analogs of (E,E)-8,10-dodecadien-1-ol, the main pheromone component, in codling moth (Cydia pomonella L.).

Pest monitoring and control of the codling moth,Cydia pomonella L., have been developed using the main pheromone component of this species, (E,E)-8,10-dodecadienol (codlemone). However, the activity of codlemone is not satisfactory for pest control by mating disruption. Thus, we have synthesized halogenated analogs of codlemone to see if they could be used as new agents for pest control of the codling moth. Their biological activity was measured by electrophysiological techniques. In EAG screening, codlemone was the most active compound. F(10,11)-codlemone [(E,E)-10,11-difluoro-8,10-dodecadienol] and Cl-codlemone [(E,E)-11-chloro-8,10-undecadienol] elicited significant EAG responses, F(10,11)-codlemone triggering responses not significantly different from responses to codlemone. EAG cross-adaptation experiments and single sensillum recordings revealed that these compounds were detected by the same receptor neuron type as codlemone. No competitive inhibition with codlemone was observed from nonactive compounds. In field trapping, F(10,11)-codlemone and Cl-codlemone were more attractive to male codling moths than codlemone itself. Possible explanations of this activity are discussed.