HISTORY
Emerald Ash Borer (Agrilus planipennis) is an invasive, wood boring beetle that feeds on the interior tissues beneath the bark of ash trees (Fraxinus spp.). EAB was likely introduced into the United States in 2002 via shipping crates brought over from Asia. Since then, EAB has killed millions of ash trees across many states. Feeding by EAB larvae, the immature stage, kills ash trees within 2-4 years.
EAB MANAGEMENT
EAB was first discovered in Bellevue in 2017. Since then, the Village has removed approximately 1000 ash trees and replaced approximately 600 of those removed ash trees from the public tree inventory. The Village dedicated a lot of time to complete tree removals along streets within a short time, since most risk associated with standing dead trees was with ash that lined streets. Current EAB tree removal efforts will focus on trees within parks, along trails, at facilities, and other public property.
EAB TREATMENT
There are several trees within Bellevue that are treated with insecticide to prevent the attack of EAB on the trees. The Village of Bellevue Forestry Department has chosen to treat some ash trees within parks due to the significance of the trees, whether that be age, size, or location. You may see some ash trees along streets that are treated at the cost of property owners adjacent to the trees. While the population of ash trees has dropped dramatically, there are a few trees that will remain as a legacy to one of the most popular and resilient trees that once lined our streets.
THE FUTURE THE URBAN FOREST
You may have noticed the diversity of tree plantings that replaced the ash trees along streets and in parks. This is because we want to learn from the past, not repeat it. History has shown that monoculture plantings, or planting areas with all the same species, has turned out bad, first with Dutch elm disease and then with emerald ash borer. Tree species diversity increases the resilience of the urban forest and lessens the potential for devastating impacts by insects and diseases. Invasive species are not a new topic, but there will continue to be new invasive species as time goes on. The most responsible thing to do is mange the urban forest to withstand future problems.