They're a half-inch long, dark green and wanted for the slaughter of countless ash trees trees across the 17 states they have called home since they were first discovered in Michigan in 2002.

Believed to have made their way from Asia to the U.S. as stowaways in wood shipping crates, emerald ash borers (EABs) first took hold of northern Kentucky in 2009; three years later, they're found in 21 counties throughout the state.

"This sucker has spread throughout lots of states in the U.S. and most of the movement has been due to people accidentally moving it, so the likelihood of it popping up anywhere is just as good as anywhere else," Jody Thompson, environmental scientist with the Kentucky Division of Forestry told the Hazard Herald.

Thompson said it's only a matter of time before the whole state is infested.

But it doesn't stop there.

The same could shortly be true of the continental United States given the EABs ability to disappear deep inside trees that are then carted throughout the country.

Measures to combat the infestation have been conducted on a state-by-state level.

New York, for example, recently announced an emergency regulation to expand the EAB quarantine area effective May 1.

In total, the insect is responsible for the destruction of over 50 million ash trees in the U.S., with most dying within two to four years of infestation, according to New York's Department of Environmental Conservation.

Fortunately, ash trees are quick and easy to grow.

"However," Thompson said, "there is a possibility of the ash tree, in our future, being wiped out of our forests, and we have seen that before (with other species)."

Among the hardest hit groups are Native Americans for whom the ash tree holds not only religious and social significance, but economic as well given its use in traditional basket weaving, pipes and flutes, lacrosse sticks and medicinal remedies.