Impacts of urban land cover on the distribution of emerald ash borer associated parasitoids

The emerald ash borer, Agrilus planipennis, has caused mass ash mortality in both traditional and urban North American forests. An ongoing integrated pest management study is investigating the impacts of introduced parasitoid biocontrol agents, Spathius galinae and Tetrastichus planipennisi, in the urban environment of Syracuse, NY. Both parasitoids were released in 2015 and are now established alongside native generalist parasitoids. In 2019,2020, and 2021, yellow pan traps (YPTs) were deployed to assess parasitoid distribution in the urban environment. Capture data was analyzed to assess whether distribution of parasitoids was impacted by urban land cover characteristics. The presence of S. galinae was negatively correlated with the presence of impervious surfaces in 2020, but appears to have dispersed throughout the system by 2021. Tree DBH was a significant negative predictor of T. planipennisi presence in all three years, consistent with the agent’s oviposition behavior. The presence of native Atanycolus cappaerti and Phasgonophora sulcata could not be assessed in 2019 or 2020. In 2021 presence of both natives postively positively with declining canopy condition. Results indicate that biological control services for the control of the emerald ash borer may be distributed throughout the urban environment due to the successful dispersal of S. galinae by 2021.