Michigan brown marmorated stink bug report for September 15, 2015

Brown marmorated stink bug activity continues to increase in Berrien County; adults and nymphs were found feeding on apples. Damaged peaches by BMSB near Grand Rapids has been reported for the second year in a row.

Brown marmorated stink bugs on an apple near Niles, Michigan. Photo by Bill Shane, MSU Extension
Brown marmorated stink bugs on an apple near Niles, Michigan. Photo by Bill Shane, MSU Extension

In the 11th week of monitoring, we are tracking a significant increase in brown marmorated stink bug (BMSB) nymphs and adults collected from traps at four locations in Berrien County. Two of the traps are in urban locations and two of the traps are in commercial apple orchards – these are the same sites we have been monitoring all season for the last three years.

Fruit samples with suspected BMSB damage continue to come in from across southern Michigan. So far, the damage we have seen in these pear and apple samples can be attributed to physiological problems associated with nutrient deficiencies or disease, not feeding by BMSB. However, one peach orchard on the southwest side of Grand Rapids, Michigan, which we have been monitoring closely because of damage found there last year, has confirmed damage by BMSB again this year. Also, BMSB nymphs and adults were found feeding on apples on an orchard border in southeastern Berrien County this past week near Niles, Michigan.

Damage to fruit from BMSB feeding can be confused with several disease or nutrient deficiencies, depending on the particular fruit that is affected, so it is important to involve your local Michigan State University Extension fruit educator to help determine what caused the damage or send samples to MSU Diagnostic Services. Visual inspection of orchard edges for the presence of fruit injury, or for the insects themselves, is recommended, but for most of the state, numbers are still well below levels that would trigger specific control measures against BMSB. Current management practices aimed at other late-season insect pests are likely to be providing some protection against the few BMSB that may be present in orchards near known hotspots such as in Berrien County.

The area of influence for a single baited trap appears to be relatively small, so it is important when using them to monitor for this pest to place them near favored plant hosts and to combine trapping with other sampling methods such as limb-jarring of fruit trees or sweep-netting in orchard edges close to woodlots and riparian areas.

For more information about BMSB management should populations reach levels that would require control, please refer to the MSU Extension Bulletin E0154, “2015 Michigan Fruit Management Guide.” To learn more about how to monitor for BMSB, distinguish it from other similar-looking stink bugs and what plants it favors, visit MSU’s Brown Marmorated Stink Bug website

The purpose of the MSU Extension BMSB monitoring network and weekly report is to provide early warning should population increases of BMSB occur in areas where susceptible crops are grown. Based on what is currently known about the biology of BMSB and its favored crop and non-crop habitats, commercial fruit and vegetable plantings have been selected that are adjacent to riparian habitats, woodland, soybean fields, major transportation corridors or various combinations of these attributes. Traps are baited with a commercially available lure and have been set up in apples, stone fruits (peaches, plums, sweet and tart cherries), blueberries, grapes, strawberries and a variety of vegetable crops. Several urban locations where BSMB were reported last year are also being monitored.

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