Courtesy Rutgers UniversityYellow sticky card traps laced with pheromones caught significantly more cranberry weevils in blueberry fields than untreated traps.A blend of four pheromones caught significantly more cranberry weevils on yellow sticky traps than unbaited controls.
By fine-tuning the trapping, growers can use more spatially targeted management techniques that could reduce the use of pesticides, according to a news release.
Cranberry weevils attach highbush blueberries in New Jersey and cranberries in Massachusetts.
The larvae feed and develop inside flower buds, preventing formation of fruit.
Control strategies target the mobile adults.
Monitoring of adults starts at bud well and continues through bloom—about two months.
Weevils tend to aggregate at field edges, so monitoring focuses along those areas.
In blueberries, growers have traditionally used beat trays or have visually surveyed buds and blossoms for the pest or injury.
Recently, researchers at Rutgers University identified the main chemical components of an aggregation pheromone.
In field trials, university researchers found that yellow sticky traps laced with four of the components caught significantly more weevils than unbaited traps.
The results can be used to develop a better monitoring lure as well as a baited trap-plant control strategy.
Knowing where the weevils are congregating will allow growers to just target that area with insecticides.