Range of action of moth sex‐attractant sources

Observations and experiments which indicate the range of attraction of a sex‐attractant source are distinguished from those which show its range of stimulation or sampling range. Published evidence of these ranges for lepidopteran sex‐attractant sources is reviewed. In particular, evidence for the values of these three parameters for traps containing 100 μg of synthetic sex‐pheromone of the pea moth, Cydia nigricana (F.), is presented, including the results of a timed mark and recapture experiment. It is concluded that for C. nigricana the ranges of attraction, stimulation and the daily sampling range for such a source placed in a cereal crop are at least 200, 500 and 500 m respectively.