Growing organic crops, which means avoiding even safe insecticides, has a down side. According to a notice from Michigan’s Department of Agriculture, a potentially serious threat to food production has been detected in the Mitten State. At risk is the state’s crops of cabbage, broccoli, cauliflower and related food plants. The pest, known as the Swede midge (Constarinia nasturii) has been detected in the state for the first time five organic production fields in Sanilac County, which borders Lake Huron. The above plants belong to a family called Brassicaceae (also called Cruciferae or crucifers).
Damaged row crops
Widely cultivated, with many genera, species, and cultivars being raised for food production such the above-mentioned, as well as garden cress, bok choy, and brussels sprouts. The alternate name for the family (Cruciferae, New Latin for "cross-bearing") is derived from the shape of their flowers, whose four petals resemble a cross. Ten of the most common cruciferous vegetables eaten by people, known colloquially as cole crops, are in a single species (Brassica oleracea).
The larvae of the pest cause swelling and severe distortion of young plant tissues, resulting in the death of the growing tip or the development of blind or multiple heads in cruciferous plants. Secondary bacterial infections are common. The Swede midge is a threat to both conventional and organic growers, but organic growers may be at greater risk because they lack effective chemical control options.
Authorities at the Michigan Department of Agriculture and Rural Development and Michigan State University do not know how the pest was introduced into the state.
Swede midge is native to Europe and southwest Asia. It was identified in North America in 2000, when it was first discovered in Ontario, Canada. It made the jump to the United States in 2004, where it was discovered in Niagara County
, New York. Since then it has spread to at least seven states and six Canadian provinces.
A relatively weak flyer, Swede midge most easily spreads to new areas in infested transplant material. It will also show up near infested crops grown in the prior season, especially downwind of them.
Michigan State University Extension agents will be working to determine the extent of the infestation in Michigan, developing monitoring and control recommendations, and educating growers. Farmers are being advised to take the following measures:
· Use clean transplants
· Rotate to non-crucifer crops every two or three years
· Work with MSU Extension on Swede midge monitoring
· Insecticide applications
In Michigan, vegetables are grown on nearly 3,000 farms. Many of these are small, having 15 acres or less. However, most of Michigan's vegetable production is produced on farms growing more than 100 acres. Michigan harvested vegetable crops on 159,000 acres in 2012 with a farm gate value of $463 million (ranking seventh nationally). Most of Michigan’s vegetable production is located in counties in the lower two-thirds of the state’s Lower Peninsula. Michigan growers produced 77.3 million pounds of cabbage worth $11 million.