In 2017 over 3100 farms across the North Central Region (NCR) dedicated 4,928 acres to strawberry production, with an economic value of $17.5 million for growers in Michigan, Ohio, and Wisconsin, alone. Growers in Wisconsin and the Midwest have identified Lygus lineolaris, the tarnished plant bug, as their primary insect pest of concern. Although frequent chemical intervention remains the strategy of choice for managing TPB, it is costly and has led to widespread insecticide resistance in populations across the Southern United States. Trap cropping may provide an effective, sustainable alternative management strategy. Trap cropping has proven highly effective against other Lygus species in California and Europe, and we expect that it can be employed to improve TPB management in the NCR. Behavioral laboratory assays conducted in our lab support this hypothesis, suggesting that TPB prefers alfalfa over strawberry. However, additional work is necessary to determine whether this preference can be exploited in the field. This project aims to assess the impact of incorporating perimeter plantings of alfalfa to manage TPB in strawberry and provide growers with an optimized cultural control strategy for this devastating pest.
Trap crops concentrate insect pests away from a cash crop, reducing damage to the main crop and the cost of chemical treatments, thereby increasing farm profitability. In California, intercropping strawberries with alfalfa to manage Lygus hesperus reduces management costs by 78%, increasing profitability by more than $725/acre. Moreover, incorporating alfalfa strips has been shown to promote natural enemy communities in California strawberry, and the reduction in pesticide applications will in turn reduce the environmental and social costs associated with TPB management. By working with stakeholders to develop an easily-implemented, low-maintenance, and proactive strategy for managing the primary strawberry pest in the NCR, we will improve the profitability and sustainability of strawberry production in our region.
We will determine the impact of alfalfa strips on 1) TPB abundance and 2) beneficial and pest arthropod communities in the trap and cash crops, determine the extent of TPB movement between trap and cash crops, and assess the potential of plant kairomones to improve attraction and retention of TPB in the trap crop. We will then disseminate our findings to stakeholders in Wisconsin and throughout the NCR via articles, blogs, and presentations at grower conferences and field days.
Project objectives from proposal:
1) Determine the efficacy of alfalfa trap cropping as a cultural control strategy for managing TPB.
2) Assess the impact of alfalfa trap cropping on beneficial and pest arthropod communities.
3) Determine the extent of movement between the trap crop and the cash crop.
4) Assess the potential of improving trap crop attractiveness with kairomones.
5) Disseminate findings to stakeholders throughout the NCR.
Results from this research will provide growers with a new sustainable cultural control strategy, which will help reduce the need for pesticide applications to manage TPB, the most devastating pest of strawberry in the NCR.