TRAVERSE CITY — Spotted wing Drosophila (SWD) and Brown Marmorated Stink Bug (BMSB) are two invasive insect pests that pose threats to Michigan’s fruit production.
Both pests have been detected in the state by the Michigan State University Extension field and campus fruit team. SWD was first found in blueberries in fall 2010, and since, populations have increased dramatically in many fruit crops across the state: cherries, blueberries, strawberries, black berries, and red raspberries. In most fields and orchards, this insect is now considered a key pest that requires a well-timed control program to protect fruits from infestation.
Brown marmorated stink bug, on the other hand, were first found in the state in very small numbers in 2011 and 2012, but late into 2013, BMSB numbers increased in isolated hot spots and adults were detected in residential areas, primarily in the southern half of the Lower Peninsula. Up until this point, no controls have targeted BMSB, but the potential for the BMSB population to increase is inevitable, and Michigan growers will likely have to implement new management programs to control this pest within the next 1 to 3 years.
Spotted wing Drosophila, a native pest of Southeast Asia, can produce many generations in a relatively short amount of time, and the optimal development of SWD is between 65 to 70°F, which are normal conditions for a Michigan growing season. Under these conditions, the generation time can be as short as 12 days. Because SWD reproduces so quickly under optimum conditions, the first catch information is vital to activate pest management programs to prevent rapid population increases and potential infestations in a region.
The BMSB was introduced from Asia 20 years ago and has a host range of over 300 known plants, including many fruits commercially grown in Michigan. Thus, BMSB has the potential to dramatically reduce the quality of peaches and cherries produced in MI, but BMSB is also a primary concern for apple producers.
Because first detection and general knowledge and understanding of these two new invasives are vital to subsequent informed control decision-making by Michigan fruit growers, our 2014 efforts will provide Michigan growers with up-to-date information on SWD and BMSB status in apples, cherries, raspberries, strawberries, and blackberries through a coordinated intensive statewide trapping system for the presence of SWD and BMSB. The MSU Fruit Team looks forward to helping Michigan’s fruit industry face the challenges of new invasive insects pests this coming season.
Dr. Nikki Rothwell is the district horticulturist at the Northwest Michigan Horticultural Research Center in Bingham Township.