Asian longhorned beetle bioassays to evaluate formulation and dose-response effects of Metarhizium microsclerotia

Authors: CLIFTON, ERIC - Cornell University; GARDESCU, SANA - Cornell University; Behle, Robert; HAJEK, ANN - Cornell University

Submitted to: Journal of Invertebrate Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/18/2019
Publication Date: 3/19/2019
Citation: Clifton, E.H., Gardescu, S., Behle, R.W., Hajek, A.E. 2019. Asian longhorned beetle bioassays to evaluate formulation and dose-response effects of Metarhizium microsclerotia. Journal of Invertebrate Pathology. 163:64-66. https://doi.org/10.1016/j.jip.2019.03.005.
DOI: https://doi.org/10.1016/j.jip.2019.03.005

Interpretive Summary: The Asian longhorned beetle is an invasive wood boring beetle with great potential for causing economically important damage to many tree species in North America. The entomopathogenic fungus Metarhizium brunneum strain F52 is an effective at killing Asian longhorned adults and can be cultured then formulated into dry granules for application to trees. Increasing the application rate of these granules killed beetles to prevent egg laying. This information supports the development of this fungus as a safe biological insecticide able to control this invasive pest without the use of chemical insecticides, especially for ecologically sensitive or urban environments.

Technical Abstract: The Asian longhorned beetle, Anoplophora glabripennis, is an invasive wood boring beetle with great potential for causing economically important damage to many tree species in North America. The entomopathogenic fungus Metarhizium brunneum strain F52, registered for commercial use in North America, is effective at killing A. glabripennis adults. The M. brunneum fungus can be cultured to produce dry microsclerotia granules, which have extended shelf life and yield large numbers of infective conidia. Field and laboratory studies were conducted with two formulations and five application rates of M. brunneum F52 microsclerotia granules that could be applied to trees. Anoplophora glabripennis adults exposed to M. brunneum F52 with or without a humectant gel had similar survival times. There was a clear trend of decreasing A. glabripennis survival times with increasing conidial densities. Adding humectant to a formulation of M. brunneum F52 microsclerotia may not improve its efficacy for killing A. glabripennis adults. However, increasing the application rate of microsclerotia granules would increase conidial densities on treated surfaces and, ultimately, kill A. glabripennis adults faster.