ARS | Publication request: Use of Beauveria bassiana and imidacloprid for control of emerald ash borer in an ash nursery

Submitted to: Proceedings of the Emerald Ash Borer and Asian Longhorned Beetle Research and Development Review 2006
Publication Type: Abstract Only
Publication Acceptance Date: February 1, 2007
Publication Date: March 1, 2007
Citation: Vandenberg, J.D., Castrillo, L.A., Liu, H., Griggs, M., Bauer, L.S. 2007. Use of Beauveria bassiana and imidacloprid for control of emerald ash borer in an ash nursery. Proceedings of the Emerald Ash Borer and Asian Longhorned Beetle Research and Development Review 2006. p. 56.

Technical Abstract: We wish to determine the potential of Beauveria bassiana strain GHA, alone or in combination with imidacloprid, for control and management of emerald ash borer (EAB), Agrilus planipennis. We have undertaken this work at a commercial tree nursery in southern Michigan within the EAB-infested area. Approximately 400 Fraxinus pennsylvanica and F. americana in three planting areas were arrayed in a randomized complete block design. Treatments consisted of fungus alone, imidacloprid alone at two rates, fungus plus the low rate of imidacloprid, and a formulation blank as control. Imidacloprid was applied as an early season drench in late May, and the fungus and formulation blank were applied with a hydraulic sprayer three times at biweekly intervals in June and July. We monitored spore deposition by washing leaves and bark samples and using dilution plate counting. We estimated spore persistence on leaves for up to 6 weeks after the final spray and we will continue monitoring survival on bark and in soil throughout the study. We counted EAB emergence holes up to 2 m high on each tree. We observed emergence from only 5 trees but observed beetle activity within our plots and on ash trees nearby. We determined that up to 4 genotypes of B. bassiana were present in soil before any sprays and that none of them was strain GHA. After sprays, we readily reisolated strain GHA from leaves, bark and soil. Adults trapped within the plots were infected with the GHA strain. This was the first year of a multi-year study.