An insect recently found in Franklin County in Maine, the swede midge, poses an economic threat to those raising broccoli, cauliflower and other members of the brassica family. The swede midge is a member of the fly family. Once established it is difficult to get rid of. Native to Europe and southwestern Asia, the insect was first discovered in Canada in 2000 and in New York in 2004.
UMaine Cooperative Extension Agriculture and Non-Timber Forest Products Professional Dave Fuller said he visited a Farmington grower’s broccoli fields four times to examine crops that weren’t growing normally.
“As is typical in a new pest situation, I wasn’t able to figure out what was going on at first. Fuller said it was three weeks ago that he discovered the insect. Verification that it was swede midge wasn’t confirmed until last week. He worked with Karen Coluzzi, the invasive insect specialist with the Maine Department of Agriculture. She sent specimens to the United States Dept. of Agriculture for an official declaration.
Maine is the last New England state to have found these flies. “They have only been found in Franklin and Aroostook counties that we know of,” Fuller said. “Aroostook has thousands of acres of brassicas. They’re a big crop there.”
The adult fly is about two millimeters in size. The larva, or maggot, is what causes the damage. “The maggots go after the active growing points, or meristems,” Fuller said. “In Brussels sprouts, the sprouts are missing. Broccoli plants are scarred, no heads form. It’s the same with cauliflower.
