Michigan spotted wing Drosophila report for June 28, 2016

Traps are detecting spotted wing Drosophila throughout the network; susceptible crops need to be protected.

This is the Michigan State University Extension spotted wing Drosophila (SWD) Statewide Monitoring Network report. Traps are now up at more than 150 different locations for the 2016 season. For traps collected during the week prior to June 21, 32 females and 8 males for a total of 39 SWD flies were captured from 18 out of the 152 traps that were checked during that week. So far this season, SWD adults have been captured in traps baited with commercial lures in strawberry (Ottawa County), blueberry (Allegan, Berrien, Ottawa counties), raspberry (Allegan, Berrien, Van Buren counties), grape (Berrien County) and cherry (Allegan, Antrim, Berrien, Grand Traverse, Kent, Macomb and Oceana counties) blocks. Although average trap catch over the entire network is less than one SWD fly per trap, ripening fruit are beginning to be at risk for infestation if not protected - particularly in the southwest and fruit ridge growing areas.

SWD graph for Northern LP

SWD graph for Sourthern LP

SWD graph for all sites

Bars represent the average number of SWD flies caught in monitoring network traps each week. Dots represent the percent traps that captured SWD that week. The shaded bar across each graph represents the proposed threshold for triggering management of the pest in susceptible crops. Northern Lower Peninsula (LP) encompasses all network traps in counties north of and including Clare in the Lower Peninsula. Southern LP encompasses all network traps in counties south of Clare in the Lower Peninsula.

Regional summaries of fly captures over the last four weeks suggest populations are still low in the northern Lower Peninsula (Antrim, Benzie, Grand Traverse, Leelanau), but the number of traps capturing SWD flies continues to rise in the fruit growing counties being monitored in the southern Lower Peninsula.

Traps in the network are baited with commercially available lures and placed in susceptible crop fields or orchards, or in a location adjacent to susceptible crops, in areas where SWD infestation has been recorded in the past. Commercial plantings include strawberry, blueberry, raspberry, grape, tart and sweet cherry, peach and plum. Counties included in the 2016 trapping network are Allegan, Antrim, Benzie, Berrien, Genesee, Grand Traverse, Ingham, Ionia, Kalamazoo, Kent, Leelanau, Lenawee, Livingston, Macomb, Mecosta, Monroe, Oakland, Oceana, Ottawa and Van Buren.

For the most current recommendations for monitoring this pest, please refer to “Monitoring traps for catching spotted wing Drosophila.” You can find out more about how to identify and manage this pest in fruit crops by visiting MSU’s Spotted Wing Drosophila website.

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