Researchers continue to address the challenges posed by a fruit fly, spotted wing drosophila (SWD), which affects Michigan cherry farms, responsible for 70% of America's tart cherries. Originating from Asia, these pests reproduce rapidly in the warm July months, leading to increased populations, making control efforts essential.
Pesticides have shown limited effectiveness against SWD. Michigan State University suggests using traps made from plastic containers with apple cider vinegar and sticky cards. Yet, experts continue exploring alternative biological control methods.
Michigan State University researchers have introduced natural predators like the samba wasp and the newly added ronin wasp. According to Nikki Rothwell from the Northwest Michigan Horticulture Research Center, "This wasp lays an egg inside the SWD larva, and then the wasp egg hatches inside and then it eats the bug from the inside out." These wasps specifically target SWD, but initial releases in cherry and blueberry farms showed limited results in forming colonies.
Another approach is modifying the behavior of the North American parasitoid wasp in laboratory settings. Michigan State University Department of Entomology reports that over subsequent generations, these wasps adapted to prey on SWD effectively.
Cherry farmer Jack King notes, "Before the invasive species came in, native cherry fruit flies were easier to deal with." The swift reproductive cycle of SWD, producing a new generation approximately every seven days, results in populations that require constant monitoring. Degree-days, a measure for tracking fruit fly behavior relative to temperature, assist farmers, like King, in timing preventive actions.
Farming practices, such as maintaining low grass and pruned trees, have been suggested by researchers to naturally deter SWD presence. Rothwell mentioned, "We opened up the canopies and we found that we could reduce 40% (of SWD) with no insecticide."
Farmers like Rich Friske emphasize the dynamic and ongoing nature of combating SWD and value research for adapting strategies. Both Friske's and King's farms have U-Pick programs, allowing consumers firsthand experiences with cherry picking while highlighting local agricultural practices.
Source: Detroit Free Press
