Abstract: It has been found that the acyl fluorides corresponding to aldehydes which have a sex attractant effect upon certain insects, in particular but not limited to those of the genus Lepidoptera, cause occurrence of the hyperagonist effects in males of the appropriate species wherein the claspers and genitalia were extended irreversibly and the upwind flight towards pheromone sources is disturbed by rapid out-of-plume motions. This effect is most useful in disruption of mating patterns. There are also provided certain novel acyl fluorides having the foregoing properties.