Abstract

Investigation of how to manage swede midge, a newly arrived invasive insect pest that threatens agriculture in New York and nationally.

Issue

Cabbage and other cole crops (broccoli, cauliflower, Brussels sprouts, etc.) grown in New York have an annual farm gate value that approaches $100 million. A recently discovered insect pest threatens these important crops. The swede midge (SM), Contarinia nasturtii Kieffer is a common and endemic pest in many cabbage-growing regions of Europe. In 2000, SM was identified in Ontario, Canada, the first record of occurrence in North America. Cole crop loss on some Canadian farms due to SM has been reported to be as much as 85 to 100 percent. The concern of New York growers is whether this insect would eventually enter the U.S. and what could be done to control it.

Response

Research was initiated at Cornell's Department of Entomology at the New York State Agricultural Experiment Station in Geneva that focused on developing a proactive approach for managing SM. Because the insect can be moved through contaminated plants and soil, as well as through its own flight, we believed there was a high probability that it would be found in New York and eventually in other parts of the U.S. We imported a population of SM and keep it in our laboratory to study control tactics. We have found that foliar insecticides can play an important role in reducing populations of SM. However, our studies indicated that seeds can be treated with some insecticides to provide excellent control with far less use of the active ingredient. Additional studies indicate that applying some insecticide as a drench at the base of the plant can also provide excellent control. We are also investigating whether some commercially produced varieties of these crops have a resistance to SM and whether cultural practices such as deep plowing can reduce populations in the field. In addition to the work on managing SM, we worked with Cornell Cooperative Extension on a survey for detecting SM in New York. In the summer of 2004, these efforts led to the first detection of SM in the U.S. Because of the difficulty in determining the species through morphological characteristics, we used molecular methods and have taught these techniques to USDA personnel as they begin to conduct a wider survey of this recent invasive insect in the U.S.

Impact

The impact of SM to NY's vegetable industry could be profound. However, by developing a management strategy prior to its first detection, NY growers will be in a far better position to manage the pest than were Canadian growers. The studies conducted at Cornell, with the assistance of Cornell Cooperative Extension personnel, have led to a Best Management Practice (BMP) Program that will be used in NY and throughout the U.S.

Funding Sources

• State or Municipal (e.g., NYSDAM)
• CCE
• Cornell Dept of Entomology-Geneva

Collaborators

• NYS Department of Agriculture and Markets
• Department of Environmental Sciences, University of Guelph, Ontario Canada
• Ontario Ministry of Agriculture and Food (Canada)

Key Personnel

• Dr. Quinjun Wu, Visiting Scientist
• Entomology Department, Cornell (Geneva)
• Dr. J. Kikkert, Cornell Cooperative Extension
• Dr. Ping Wang, Assistant Professor
• Entomology Department, Cornell (Geneva)
• C. Hoepting, Cornell Cooperative Extension