Insidious Insects

Plants, animals, and insects grow and evolve based on the dynamics of their native ecosystems. Competition and predation keeps their populations in check. It is when specific species are inadvertently brought to a new ecosystem where the native flora and fauna are ill equipped to deal with this new threat that they become a major problem. Emerald Ash Borer (EAB) is that threat. Agrilus planipennis is a small metallic wood boring beetle native to Northern China, Mongolia, Japan, Korea and Eastern Russia. In their native ranges, these beetles are a natural part of nutrient cycling. The adults lay eggs on bark. The larvae burrow into the tree feeding on phloem and inner bark tissues. The damage caused by the larval stage of the EAB prevents the transport of nutrients and water through the tree. Eventually the tree is girdled and in a few years dies.
The EAB was introduced to the US in the 1990’s initially discovered killing Ash trees in Southeastern Michigan in 2002. In the US this small harmless looking beetle is causing serious damage to our native Ash populations. After the wake of another invasive species, Dutch Elm Disease, many municipalities and property owners filled the voids left by the dead and dying Elms with Ash trees. Like Dutch Elm Disease, Emerald Ash Borer not only threatens the composition of our native forest ecosystems but also the property values and aesthetics that Ash trees provide in an urban environment. The damages suffered by the forestry industry; private landowners; and, municipalities are estimated to be in the tens of millions of dollars. After the EAB’s initial detection in 2002 the insect has since spread as far south as Tennessee, West to Minnesota, East to New York and even into parts of Canada.
While the EAB can naturally spread on its own, about 1 mile annually. It is people that have increased the spread of this insect. The transportation of firewood, logs, infested trees and nursery stock by humans has caused the affected range of the Emerald Ash Borer to increase in size more rapidly that the insect possible could on its own. There are Federal and State quarantines in place to minimize the impact of EAB on uninfected areas through the transport of trees and logs. Many states including Wisconsin have placed bans on the transport of firewood but this is difficult to regulate and enforce. Ultimately people are going to need to be proactive if we are to be successful at mitigating the Ash losses due to the EAB. We must be environmentally conscious and think before we recreate in the out of doors or try to make a buck of the sale of Ash trees. These little critters are great hitch-hikers. People should monitor their areas for the spread of EAB and comply with all State and Federal regulations. It is not advisable to plant any new Ash trees because there is no sure way of eradicating the EAB. For more information on Emerald Ash Borer please visit the following sites.







(http://na.fs.fed.us/fhp/eab/)

(http://www.emeraldashborer.info/