Journal of Pest Science (2022) 95, 1081-1090

Jian J. Duan, Roy G. Van Driesche, Jonathan Schmude, Ryan Crandall, Claire Rutlege, Nicole Quinn, Benjamin H. Slager, Juli R. Gould and Joseph S. Elkinton (2022)
Significant suppression of invasive emerald ash borer by introduced parasitoids: potential for North American ash recovery
Journal of Pest Science 95 (3), 1081-1090
Abstract: Successful management of invasive forest pests with sustainable approaches, such as biological control, is critical to the restoration of the affected or damaged forest ecosystems. Several parasitoids introduced from Northeast Asia were released between 2015 and 2017 in several northeastern states of the USA for biocontrol of the invasive emerald ash borer (EAB), Agrilus planipennis. Using life tables to estimate the pest population growth rate, we evaluated the impact of two introduced parasitoids (Spathius galinae and Tetrastichus planipennisi) on EAB population dynamics in five ash-dominated hardwood forests in three Northeastern U.S states. We observed ~ 76% decrease in average densities of live EAB larvae to a low density (< 7 live larvae per m² of tree phloem) from 2015 to 2020. This reduction in pest density was driven primarily by the significant increase in parasitism rates (from 35 to 78%) by S. galinae, along with low-to-moderate levels of mortality from local generalist natural enemies, such as woodpeckers. Spathius galinae alone caused a 31–57% reduction in the net pest population growth rate from 2018 to 2020. These findings demonstrate that in the recently invaded ash forests in the Northeastern USA, timely introduction of specialized natural enemies, such as S. galinae, along with local generalist natural enemies, may significantly suppress the invasive pest populations to low densities, allowing surviving trees to recover.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Jian J. Duan, Roy G. Van Driesche, Juli R. Gould

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
evaluation - screening - selection
classical biocontrol/new introduction

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Agrilus planipennis	Ash (Fraxinus)	U.S.A. (NE)
Tetrastichus planipennisi (parasitoid)	Agrilus planipennis	Ash (Fraxinus)	U.S.A. (NE)
Spathius galinae (parasitoid)	Agrilus planipennis	Ash (Fraxinus)	U.S.A. (NE)