Flight phenology and dispersal of Grapholita molesta (Busck) as affected by rubidium enrichment and orchard hosts

The oriental fruit moth (Grapholita molesta Busck) is recognized as a major lepidopteran pest of apple and peach crops in Pennsylvania. G. molesta is suspected to migrate between apple and peach crops depending on the time of the growing season and the seasonal suitability of the crops for its progeny. In Pennsylvania, apple and peach orchards are often planted within 50 meters of each other. These crop-related factors, coupled with prospects for sex pheromone mating disruption over large areas (or, "area-wide mating disruption") have made understanding G. molesta movement patterns imperative for management programs incorporating synthetic sex pheromones. Therefore, I investigated the temporal and spatial dispersal of male G. molesta in the presence of apple and peach orchards. Sex pheromone trapping; mark-release-recapture techniques; weather data; a geographic information system (GIS) and a variety of statistical methods were employed to make inferences about environmental variables in apple and peach orchards that influence male G. molesta dispersal.; Adult female and male G. molesta reared on a dietary substrate mixed with 6,000 mg Rubidium Chloride (RbCl) per L liquid diet were successfully labeled with rubidium (Rb) above a threshold (i.e. , the amount of Rb in unlabeled moths + 3 SD) considered sufficient for labeling in mark-release-recapture studies. The Rb had no adverse effects on development or reproductive behavior. Both male and female moths labeled with Rb as larvae retained a signature detectable above the baseline up to seven days after adult eclosion. In wind-tunnel bioassays, Rb-labeled male G. molesta were observed for completion of successive behaviors leading to flight to a sex pheromone point source. Males were more likely to exhibit lock-on behavior than unlabeled moths, despite insignificant differences in the numbers of moths completing the sequential behaviors preceding lock-on.; Significant temporal variation was detected in counts of four broods of wild moths captured in sex pheromone traps in apple and peach research orchards from 1999 to 2005 at The Pennsylvania State University Fruit Research and Extension Center (PSU-FREC) in Biglerville, PA. After accounting for variations due to time, it was concluded that the remaining variation in the moth trap-counts in the apples and peaches were mainly attributable to increasing resident G. molesta populations over time. Logistic growth functions were employed to generate flight curves and 95% confidence intervals based on estimated brood "cutoffs" according to accumulated degree days in each crop. (Abstract shortened by UMI.)...