Michigan spotted wing Drosophila report for July 2, 2013

New spotted wing Drosophila detections have been made in Berrien, Allegan and Ottawa counties in southwest and west central Michigan.

Editor’s note: More spotted wing Drosophila were detected in southwest Michigan and reported to us on July 3, 2013. Read the additions to the spotted wing Drosophila report for July 2, 2013, for more information on these catches.

Spotted wing drosophila (SWD) numbers have increased in southwest and west central Michigan this week. Three males were caught in blueberry traps at the edges of the blueberry fields, in woods at the edges of these fields, and within the interiors of these fields. We also caught five female SWD in the same trap locations in blueberries. One female was captured in a trap placed at the edge of a raspberry field. This week, we caught a total of four SWD in Allegan County, two in Ottawa County, and one in Berrien County. Overall, Michigan State University Extension is catching about 0.1 flies per trap and 10 percent of all the traps in the state are catching flies.

As raspberries and blueberries are ripening, growers need to be sure to keep this fruit protected through harvest. Growers should make their decisions to spray based on the presence of SWD flies and ripening or ripe fruit that are susceptible. Growers should maintain a monitoring program in these crops through harvest. For more information, see the recent MSU Extension article “Recent spotted wing Drosophila catches indicate ripening berries should be protected.”

A private consultant trapped a SWD in a tart cherry block in southwest Michigan. As sweet cherry harvest has begun in southwest, southeast and the Grand Rapids, Mich., area, growers should be monitoring these ripening fruits for the presence of SWD. Tart cherry harvest is predicted to begin later this week and into next week in the south, and these fields should be monitored for SWD. Cherries are on the list of fruits at high risk from SWD infestation.

MSU Extension SWD statewide monitoring
SWD monitoring graph

For more information on SWD and to read past reports, visit MSU‘s Spotted Wing Drosophila website.

The weekly SWD scouting report has been funded through Project GREEEN and Michigan State University Extension.  This output is generated through a scouting and reporting network of MSU Extension field staff and campus specialists. We would like to acknowledge the following team members and thank them for their weekly scouting efforts and input into this report: Rufus Isaacs, Keith Mason, Steve VanTimmeren, Larry Gut, Peter McGhee, Michael Haas, Bob Tritten, Mark Longstroth, Diane Brown, Carlos Garcia, Karen Powers and Nikki Rothwell.

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