Sen. Peters Renews Effort to Fund Research on Invasive Fruit Fly Threat

By Andi Anderson

U.S. Senator Gary Peters has reintroduced a bipartisan bill aimed at supporting ongoing research to manage an invasive pest that has troubled Michigan fruit farmers for more than a decade. The spotted wing drosophila, a small fruit fly first detected in northern Michigan about 15 years ago, has significantly changed cherry production practices.

Once considered easier to grow, cherries now require increased labor and costly insecticide applications to prevent damage.

Fruit grower and Cherry Marketing Institute board chair Emily Miezio explained the strain the pest has placed on growers.

She said, “We continue to have a loss on our crops and extreme input costs trying to keep it at bay.” The insect lays its eggs in soft fruits such as cherries and blueberries, making the affected fruit unusable.

Sen. Peters’ bill, known as the Spotted Wing Abatement Trust Act (SWAT Act), would designate $6.5 million annually for five years to support research on the pest.

Miezio emphasized the importance of long-term funding, noting, “Research that's done is not, unfortunately, done in just one sitting. It usually takes years and years of trial and error to come up with the best way.”

Researchers at the Northwest Michigan Horticulture Research Center, which is part of Michigan State University Extension, have been experimenting with various strategies to control the pest.

Nikki Rothwell, a research specialist and coordinator at the center, described an attempt involving parasitic wasps. The team was unable to retrieve those wasps for evaluation, but they later discovered another species naturally present in the environment.

Rothwell explained, “We knew that it was a predator or parasitoid of spotted wing drosophila that’s been found in multiple states.”

Consistent funding from the proposed bill could help expand research on this naturally occurring wasp, which may become increasingly important if the fruit fly develops resistance to insecticides.

Rothwell said, “We haven’t documented [insecticide] resistance yet with spotted wing drosophila here in Michigan, but it has been documented in the west. So if we don’t have insecticides to control this, what are other options? I think, probably, that’s in the back of a lot of people’s minds.”

Researchers are also interested in studying a technique used against other invasive insects: sterilizing and releasing male flies to reduce reproduction. Rothwell noted that additional funding would be crucial for exploring this method effectively.

The SWAT Act was first introduced in 2022 and reintroduced again in 2023. With its renewed introduction, growers hope it will bring long-term stability to pest management research and support the future of Michigan’s fruit industry.

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