Significant suppression of invasive emerald ash borer by introduced parasitoids: potential for North American ash recovery

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 (