Official Pest Report

Official Pest Reports are provided by National Plant Protection Organizations within the NAPPO region. These Pest Reports are intended to comply with the International Plant Protection Convention's Standard on Pest Reporting, endorsed by the Interim Commission on Phytosanitary Measures in March 2002.

Swede Midge (Contarinia nasturtii) in New York State

Country: United States

Title: Swede Midge (Contarinia nasturtii) in New York State

Not available

Report: Beginning in September 2004, Swede Midge (Contarinia nasturtii (Kieffer)), a Cecidomyiidae, was detected in the State of New York. This tiny fly (1.5-2 mm) can cause serious economic damage and/or crop loss of Brassica and other related crucifers with vegetable crops being especially hardest hit.

The fly had not been detected in North America before 2000, although; farmers in Ontario, Canada, began noticing heavy losses as high as 85 percent in their broccoli crop as far back as 1994. These losses mistakenly were blamed on soil nutrient deficiencies.

Adult Swede Midge are weak fliers. The primary avenues for introduction are believed to be through the movement of transplants, which may contain eggs or larvae, or soil, which may contain pupae. Therefore, due to environmental similarities and the potential for movement of plants and soil between Canada and New York, there was concern that this pest could become present in New York, which leads the country in cabbage production. In the summer of 2002, there was a large-scale effort to scout fields of commercial cruciferous vegetables in western New York for Swede Midge. It was not until 2004 that confirmation of the pest occurred in the western portion of the state in Niagara County. During the course of survey activities for this pest in 2005, additional positive samples were collected in the counties of Erie, Genessee, Monroe, Orleans, and Wyoming.

APHIS continues to coordinate with the New York State Department of Agriculture and Markets to conduct additional delimiting surveys for infestations of Swede Midge. A pest alert describing this insect is available on the APHIS website at:

Posted Date: Feb. 6, 2006, 9 a.m.