Under normal conditions, overwintering adults emerge from their winter hideouts in early spring to mid-June and immediately move to feed on available hosts. Photo by G. Krawczyk.
The ability to survive and reproduce on various plants and move unrestricted among various hosts is one of the main factors contributing to the continuous and quite unpredictable presence of this pest in orchards.
Since the late 1990s BMSB populations have become established in North America, with the first official identification record from Lehigh County, Pa., dated September 2001. At the time of this initial finding, the species was already well established in the Allentown, Pa., area and was reported to cause damage to various home garden products and ornamental plants. During this initial detection period, brown marmorated stink bug adults were frequently reported as a nuisance to homeowners as they tended to overwinter inside houses and other dwellings. Currently, BMSB is reported from most counties in Pennsylvania and more than 45 states across United States and in Canada.
Description and life cycle
The brown marmorated stink bug has two generations in southern Pennsylvania. Under normal conditions, overwintering adults emerge from their winter hideouts in early spring to mid-June and immediately move to feed on available hosts. The feeding of BMSB adults and nymphs are reported from more than 300 host plants. Their ability to survive and reproduce on various plants and move unrestricted among various hosts is one of the main factors contributing to the continuous and quite unpredictable presence of this pest in orchards.
Feeding damage on fruit caused by BMSB can occur throughout most of the season. Although the mechanism of BMSB feeding is similar during various parts of the season, the injury caused by stink bugs can have various appearances based on the time of the season the feeding takes place. Early feeding injury can result in misshapen fruit, while late season feeding on maturing fruit can cause the formation of necrotic tissue (corking) close to the skin surface. Sometime stink bug injuries on fruit can be confused with the physiological disorder called "corking" caused by calcium deficiency.
Monitoring and management
Visual observations remain the most accurate method to monitor the occurrence of brown marmorated stink bug adults and nymphs. Commercially available traps and lures for BMSB monitoring could also provide valuable information and help to decide if insecticide treatments are needed to manage BMSB. Stink bug traps and lures from Ag-Bio and Sterling International are available for purchase and starting from mid July should help with effective monitoring of BMSB adults and nymphs in orchards. Although traps by themselves will not control BMSB, by capturing adults and nymphs, traps can be utilized as an early warning system in orchards. With a constant threat of new BMSB adults migrating into the orchard from surrounding vegetation such as woods or field crop, monitoring traps are the most practical tools to detect the presence of this pest. Since no specific BMSB pheromones or other attractants are currently available, conventional traps are not reliable tools for the monitoring of this pest. Insecticides with various modes of action can effectively control the brown marmorated stink bug. While a number of commonly used products are effective against this pest (e.g., neonicotinoids, carbamates, or pyrethroids), the continuous challenge revolves around the unrestricted influx of new stink bug adults from surrounding vegetation and therefore causes the necessity for multiple, repeated applications of insecticides. Specific chemical recommendations for home gardeners are in Fruit Production for the Home Gardener, and recommendations for commercial growers are in the Penn State Tree Fruit Production Guide. Detailed management options and possible ways to reduce their impact on integrity of the Pennsylvania IPMsystem are discussed in "Special Section: Brown Marmorated Stink Bug--New Exotic Insect Pest" of the Penn State Tree Fruit Production Guide.