Actographic analysis of the effects of an esterase inhibitor on male moth responses to sex pheromone

The effects of 3-octylthio-1,1,1-trifiuoropropan-2-one (OTFP), a trifluorom ethyl ketone that inhibits antennal esterases, on male Mamestra brassicae r esponses to the main pheromone component have been investigated using an ac tograph. This actograph used a movement. detector based on the Doppler effe ct. The signal from the detector was digitalized and analysed on a PC micro computer to quantify male activity. When added to the air flowing through t he observation chamber OTFP inhibited the responses of male moths to the ph eromone. The number of males responding to the pheromone and the intensity of the response were decreased by OTFP. The latency of the response was inc reased and its duration decreased. These effects on the kinetics of the beh avioural response cannot be directly correlated to the inhibition of pherom one catabolism by OTFP and other targets must be involved. The high level o f inhibition of behaviour observed in presence of OTFP demonstrates the int erest of trifluoromethyl ketones as mating disruption agents for pest contr ol.