Spotted wing Drosophila: Training is essential for management and control

As spotted wing Drosophila disperse rapidly across the country, Michigan’s small fruit growers should learn how to incorporate control in their current integrated pest management (IPM) programs through MSU Extension meetings on management and control.

Not knowing how to monitor, identify and control spotted wing Drosophila (SWD) is inviting trouble at harvest time. As of June 29, 2012, all monitoring reports indicate that SWD fly activity is on the rise in Michigan. This is occurring much earlier than in 2011. The SWD appearance so early in the season means that the risk of fruit infestation may start before the insecticide applications against the blueberry maggots or Japanese beetles, which might provide protection for the early portion of the SWD attack. However, relying on our current blueberry maggot or Japanese beetle management programs for protection against SWD is a mistake.

First of all, applications against blueberry maggots occur only after the flies are detected by our monitoring devices. However, yellow sticky traps will not help with the detection of SWD. Drosophila flies belong to a different family of fruit flies and do not respond to the sticky traps. Secondly, some insecticides recommended against blueberry maggots or Japanese beetles have limited activity against SWD flies. Also, timing of insecticide applications against these pests is different from the optimum timing for SWD control. Thus, timing will make the difference between success and failure.

Without the proper training, growers will not be able to monitor nor identify the presence of SWD in their fields. This might mean that growers apply insecticides to prevent a SWD infestation without knowing if the pest is present, thus spending unnecessary resources and time. Alternatively, growers unaware of the presence of SWD in their fields may find that the pest will go unnoticed until harvest time when quality control inspections may detect infestation leading to rejection of the fruit load.

The MSU Extension small fruit program has been proactive to provide the much needed training to small fruit growers. Our aim is to help ensure that growers can continue to harvest high quality berries. We can provide assistance with checking fly identifications and we are interested in hearing about the industry’s need for further training in SWD identification. We are learning new things each week about how to monitor and control this pest, and MSU staff can assist growers in making informed choices about optimal management of SWD.

Before we plan further training programs, we want to hear about grower needs in this area. Is training during harvest season possible (we expect people are too busy)? Should training workshops be during the day or in the evening? To provide input on these questions or for assistance on issues related to spotted wing Drosophila, identification, monitoring and control, call or e-mail Carlos García at 616-260-0671.

Related MSU Extension News article: Managing spotted wing Drosophila update

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