Please consider removing any Box elder (Acer negundo) from your property this winter. These are highly susceptible to PSHB and will die within one year of infestation, this results in a mass of beetles attacking everything around it. The Southern Suburbs are a hot spot for PSHB and there have been confirmed PSHB infestations in Obs. It is far cheaper and more easily done before infection. So please, please consider removing these trees.