Apple flea weevils star at organic field day
Trained at Washington State University, Matt Grieshop is Michigan State University’s new organic tree fruit entomologist. He and his grad students are trying to find ways to control the apple flea weevil, a plum curculio-like insect , and are screening organically acceptable insecticides
If Tom Rosenfeld had known it earlier, he might have opted out. His Earth First Farm in southwest Michigan was chosen for the first field day by the recently formed Organic Tree Fruit Association, of which he was elected treasurer.
That day, June 19, however, his apple orchard was infested with apple flea weevils that had appeared early in the season, curled the leaves and filled them with shot holes, destroyed most of the blossoms before fruit was even there—and were still there, raising havoc on new shoots and leaves, on his field day.
Most growers in the East and Midwest who attempt to grow apples organically seem used to these kinds of problems and so, given lemons, they make lemonade.
Michigan State University’s new organic tree fruit entomologist, Matt Grieshop, was there and solicited input from visitors, who jumped in to help out. Apparently, there’s not much modern literature on the apple flea weevil. It erupts sporadically and is apparently “incidentally” controlled by conventional insecticides.
But this insect, which looks like plum curculio without the beak and is closely related to it, was mostly unaffected by treatments with organically approved insecticides. Rosenfeld’s orchard was not the only organic apple orchard afflicted—several in Michigan have been this year and last year as well, Grieshop said. The flea weevil may join the ranks of other insects that make life tough for organic apple growers on the continent’s moist east side.
Grieshop and his graduate students are studying the insect and figuring out how to manage it.
Tom and Denise Rosenfeld, meantime, are in their fifth year trying to make a go of organic apples. They still live in Chicago, 100 miles from their 65-acre orchard at Berrien Center, and Tom hasn’t quit his day job as a financial consultant.
You can read more about their farming efforts in a future issue of Good Fruit Grower.