Suppression of mating by blackheaded fireworm (Lepidoptera : Tortricidae) in Wisconsin cranberry marshes by using MSTRS (TM) devices

We conducted a study to optimize the deployment of our controlled pheromone release system called metered semiochemical timed release system (MSTRS(TM )) and to measure its impact on male blackheaded fireworm, Rhopobota naevan a (Hubner) (Lepidoptera: Tortricidae). The deployment pattern and pheromone emission rate of the MSTRS(TM) devices were adjusted to give optimal matin g disruption in the widely dispersed cranberry (Vaccinium macrocarpon Aiton ) beds from a perimeter-only pattern of deployment. During the first flight , disruption of pheromone source location averaged 98, 98, and 40% in the f irst, second, and third grower sites, respectively. During the second fligh t, disruption averaged 88% in the first grower site and 86% in the second a nd third grower sites. More importantly, high levels of mating disruption w ere achieved, as measured by the frequency of mating by captured free-flyin g females. About 24 and 15% fewer second-generation blackheaded fireworm fe males mated in the MSTRS(TM)-treated beds in the first and second grower si tes, respectively, compared with the check plots. In the first grower site, the mean number of matings, as measured by the numbers of deposited sperma tophores, per female captured during the second flight was 0.75 in the MSTR S(TM) beds and 1.8 in untreated beds. Number of matings per female in the s econd grower site averaged 1.0 in the MSTRS(TM)-treated beds and 1.48 in th e untreated beds.