Fruit Insect Pest Alerts: June 24, 2020

Photo: Japanese beetles on a grape leaf. Jeff Hahn, UMN.

Bill Hutchison, Suzanne Wold-Burkness, Eric Burkness, UMN Extension IPM Program, Dominique Ebbenga, and Adam Toninato Dept. of Entomology, UMN, St. Paul campus

Spotted Wing Drosophila (SWD)

Trap catches of adult SWD slightly increased this past week at our main monitoring sites; numbers increased to 1/trap/week at Forest Lake (summer raspberry), 5/trap at Chanhassen, Hort. Research Center (HRC), and 6/trap at Rosemount (fall raspberry).

For the most updated trap catch data, view the FruitEdge SWD page at: https://www.fruitedge.umn.edu/swdtrap . Note that SWD trap catch numbers are usually updated on Tuesdays or by Wednesday noon each week; trap catch comparisons are also available for 2018-2019.

SWD female (left), with close-up view of ovipositor (for egg-lay), and male (right) with characteristic dark spots on each wing (C. Guédot, Univ. of Wisconsin).

As SWD population pressure can vary considerably from farm to farm in Minnesota, the best option for monitoring is to have at least 1 to 2 traps on your farm, near berry crops. For more information on SWD traps, or how to build your own using apple-cider vinegar (ACV) traps, see: https://www.fruitedge.umn.edu/swdbiology.

Please follow this newsletter for management updates and see last week's article on SWD management.

Japanese Beetle (JB)

During the past 7-10 days, the first JB adults have been detected in several crops including fall raspberry and wine grapes, in southern MN. The first adult beetles of the season were captured in JB taps at Rosemount (Dakota Co.) at 0.50/trap/week, at the HRC near Chanhassen (Carver Co.), at 1.5/trap/week. Traps at Hastings and Forest Lake remained at zero this week.

New this year, we have also developed a JB web page summarizing weekly trap catch of adult beetles for selected locations.

Japanese beetle adult. Photo: Jeff Hahn, University of Minnesota.

Please “bookmark” the following page for quick access to trap catch updates during the growing season: https://www.fruitedge.umn.edu/pests/jb/jbtraps

As noted on the above web page, we also provide 2019 JB trap catch data for these same locations, for comparison. In 2019, JB adult populations did not begin to increase substantially until July 4th. More details regarding JB management in fruit crops will be reviewed in upcoming issues of this newsletter, as well as research updates.

For more information on managing JB in fruit crops, visit these articles:
Managing Japanese Beetle: Variety Preferences in Raspberry and Wine Grapes
Managing Japanese Beetle in Fruit Crops
Japanese Beetles in Yards and Gardens

Note: For updated insecticide control options, refer to the annually revised Midwest Fruit Pest Management Guide,. This guide is produced by UMN Extension and cooperating Midwest state Extension Specialists.

For all pesticides, it is essential to read the label prior to use, and to closely follow the Re-entry Interval (REI) and Post-harvest Interval (PHI) requirements.