Plague-like Emerald Ash Borer Spreads Through U.S. States, Killing Trees

Like the plague, the emerald ash borer is spreading across Kentucky and other states, killing thousands of ash trees. The invasive insects are relentless, and have already caused millions of dollars-worth of damage in the areas that they've infested.

The tiny insects are an invasive species, heralding from Asia.  It first arrived in 2002 in southeastern Michigan and was sited in Canada that same year. In order to kill ash tree species, the insect lays its eggs under the bark of the trees. Its larvae then hatch from the eggs and chew through the vascular tissue of the tree which transports vital nutrients and water for the plant. Eventually, the adult beetles emerge from the tree through a 1/8-inch hole. Infected trees usually die within just two years, unable to properly soak up nutrients due to the damaged tissue.

At least one county is planning to fight back, though. Bay County in Michigan is seeking a U.S. Environmental Protection Agency grant that could help treat and replace the trees damaged by emerald ash borers. Currently, the county utilizes $200,000 annually to combat the emerald ash borer. The extra money would actually help replace the trees that were lost due to the insect. The county plans to treat about 2,600 ash trees this year with a budget of $175,000 using the millage funds.

Yet there are other states that are facing even more dire threats from the insect. Maryland in particular may face some of the worst destruction.

"Emerald ash borer alone has been estimated that it will exceed nearly $230 million worth of damage to ash trees in the state alone," said Maryland's Deputy Agriculture Secretary Mary Ellen Settings in an interview with WTOP.

Currently, there's no effective way to halt the spread of emerald ash borers. However, there are some precautions. Infected trees can be injected with insecticide--it doesn't cure the tree, but can buy some time. In addition, not transporting firewood can also help keep these insects from journeying too far.

That said, the infestation is still a major issue in the U.S. It's likely that the costs will continue to stack up as the insects continue to spread.