Oriental beetle is an important soil feeding insect in NJ blueberries. Grubs feed on roots, decreasing plant vigor, leading to plant death. Imidacloprid is the only proven and labeled chemical control that growers can use. During the past three years IPM monitoring has shown an increase in Oriental beetle trap counts. A 2018 a survey sampled 115 blueberry fields, and found that 64% of the fields had grubs. Insecticide use records indicated that most growers were not treating for the insect. This was due to: 1) Most growers were not aware of the problem; 2) They lacked the time to treat since treatment timings are during the early picking season; and 3) Imidacloprid is known to be toxic to bees, and many growers feel it’s use decreases pollination quality and yield, in addition to harming bees and increasing pollination costs and problems for beekeepers.
Our objective is to evaluate two alternative controls over a commercial scale; mating disruption for Oriental beetle, and a new Bt formulation that has shown efficacy for Oriental beetle grubs. Plots will be monitored with pheromone traps for adults and root samples for larvae. Successful use of these products and practices will demonstrate 2 new strategies that can replace imidacloprid use. They are safe for pollinators and are also certified as organic practices.
We will partner with 3 growers, who will purchase 50% of the required mating disruption dispensers, and make all applications. Two on-farm meetings will be held on one of the farms.
Project objectives from proposal:
This project seeks to demonstrate how 2 alternative management strategies can be used in commercial blueberry production for Oriental beetle grub control. We will demonstrate the effectiveness of mating disruption used alone over 1 and 2 year periods. We will also demonstrate the effectiveness of the Bt, ‘beetleGONE!’ product, used alone and in combination with mating disruption treatments. This is a cooperative on-farm project, where growers will be making the applications, while we will be monitoring treatment performance, and reporting back to the participants and other commercial growers. Our objectives include the growers experiencing the results for 2 years, talking to other growers about the experience, and making presentations (Variety Farms) on their site. Successful completion of our objectives should result in further use of sustainable practices, and better control of Oriental beetle, resulting in lower grub populations and improved plant health. The project should benefit both farmers and beekeepers, since it will remove a major insecticide application that has negative effects on bees. Growers who presently don’t treat for Oriental beetle because of adverse bee and pollination issues, should change their practices and treat, knowing that their treatments will not affect pollination and improve plant health.