Biology and Management of the Hessian Fly in Northern Idaho
This project will address the biology and management of the Hessian fly, one of the most economically damaging pests of wheat worldwide. Hessian fly is of economic importance in Idaho, Washington state and Oregon. Due to the existence of virulence against the H3 resistant gene in northern Idaho and eastern Washington Hessian fly populations, utilization of multiple genes for resistance is critical to enhance durability of resistant varieties. It is important to continue the development of resistant varieties that utilize different genes for resistance, so as to provide more options for growers. Furthermore, it is important to regularly monitor the effectiveness of the presently deployed resistant varieties to determine if Hessian fly biotypes capable of attacking the resistant varieties are increasing in proportion in the fly population. The availability of adapted, Hessian fly-resistant varieties will provide Pacific Northwest wheat producers with an option to minimize the potentially increasing economic losses associated with this pest. Potential differences in adult Hessian fly survival and emergence between different tillage systems have not been examined in Idaho, so it is not clear if reduced tillage fields are contributing to greater pest infestations across the landscape. A full understanding of the influence of tillage practices on fly biology will improve our ability to adjust production practices to improve the management of this pest. A combination of laboratory and field experiments will be used. Results of this work will provide growers in the Pacific Northwest with new spring wheat varieties with resistance to Hessian fly. The project will help in the identification of effective markers for the H3 gene for Hessian fly resistance. Additionally, the project will provide information on the effectiveness of currently deployed fly resistance genes. It will also generate information on potential differences in fly survival and emergence under different tillage systems.