SWD & BMSB Update

September 1, 2016

Bill Hutchison, Eric Burkness, Suzanne Wold-Burkness
MN Extension IPM Program, Dept. of Entomology, University of Minnesota, St. Paul campus

Spotted Wing Drosophila (SWD) continues to demonstrate why it is one of the more devastating invasive insect pests in Minnesota. This has been another record year for SWD population numbers, with some locations exceeding 1500-2000/trap per week, in the metro area. This past week, most location counts declined to <100/week; with the cooler weather this week, numbers could rebound again. As noted earlier, control options with insecticides in open field systems, continues to be a challenge. Given our experience the past two years, if susceptible fruit (of any of the berry crops) is present on a farm, then the first insecticide sprays should be applied as soon as possible, and maintained on a 5-day schedule until final harvest. Harvest dates can be (must be) scheduled around the 5-day spray regime, pre-harvest intervals (PHI) adhered to, and insecticides should be rotated to minimize the risk of resistance; see the SWD management article

swd female

swd male
SWD Female, with unique ovipositor (serrated edge), capable of penetrating fruit surface (Sheila Fitzpatrick, Pacific Agri-Food Res. Centre, BC) SWD Adult Male, with characteristic spots on the wings. (Sheila Fitzpatrick, Pacific Agri-Food Res. Centre, BC)

Fortunately, based on UMN and Michigan State research, we continue to see several benefits of various High-tunnel and/or Exclusion netting options as an alternative system for SWD management.  Although our field trials this summer are not yet complete, we continued to see SWD suppression in experimental HT plots, as well as in larger HTs with a commercial cooperator.  We will make these results available this fall/winter, in preparation for the 2017 season. IPM tips and management guidelines will continue to be uploaded to this site.  Also, the SWD Trap Catch updates can be found here

Updates on Detections of the Brown Marmorated Stink Bug (BMSB) in Minnesota

BMSBIn the past 10 days, Dr. Bob Koch, Entomology, observed the first BMSB adult in an agricultural crop setting, in soybeans at the Rosemount Research & Outreach Center (UMORE Park) in Dakota Co.  Although the pest has been detected since 2010, on buildings and in various traps, this is the first occurrence of the insect that we are aware of, in a Minnesota field crop.

This past week, we also detected the first BMSB nymphs (immature stage) in a pheromone-lure based trap (lures designed to mimic sex attractants and/or aggregation attractants released by the stink bug).  This occurred at an urban location in Wyoming, MN. At this same site we have also found nymphs to be present in late summer/fall in 2014 and 2015; each of these observations is evidence of a consistent, locally reproductive population. Before the end of this field season, we may have other locations that are positive for nymphs as well as adults. Please refer to earlier issues of this newsletter for more information, and/or view out FruitEdge web page for BMSB updates

In 2016 we significantly expanded the monitoring effort for BMSB, as part of a new grant funded by the Minnesota Invasive Terrestrial Plants and Pests Center, UMN.  We are also working in cooperation with the MDA’s Invasive Species program, where the MDA has several pheromone-based traps in place for BMSB. For more information on the MITPPC, our invasive species research, also visit the MN Extension IPM Program page, at:  www.mnipm.umn.edu

The MDA web page on BMSB also provides an updated map for detections: http://www.mda.state.mn.us/plants/insects/stinkbug/bmsbmonitoring.aspx