Emerald Ash Beetle Boring into and Devouring Midwest Trees

The emerald ash borer beetle is an invasive species threatening to devour all the ash trees in Wisconsin and other Midwest states.

The city of Madison has already marked 8,500 ash trees with the feared yellow dot, a spray-painted indicator of which trees are slate for removal, the Wisconsin State Journal reported. Roughly 12,500 more - all on street terraces - are to be chemically treated later this month.

The non-native beetle species, hailing from Asia, was first spotted in Detroit in 2002 and has since spread to more than a dozen states as well as Canada - killing more than 50 million ash trees in its wake. The emerald ash borer is able to bring down entire forests because it eats the inner parts of a tree's bark that carry water and nutrients.

"We're trying to treat and save everything worth saving," Parks Division facilities operations manager Charlie Romines told the State Journal. "We understand the feelings of homeowners. But they're dealing with one or two trees. We're dealing with 20,000 ash trees on the terrace."

The combined cost of tackling these tree-killers could exceed a whopping $19.1 million by 2020, including cost of treatment, removing trees and stumps, replanting and related personnel expenses. For comparison, that budget could buy a new library branch, police station and 14 Metro Transit buses for Madison, according to the State Journal report.

City officials intend to treat the first 4,000 trees this spring and summer before resolving to removal this winter. Chemicals are injected into the trees' vascular system, a harmless process to animals, birds or other insects that land on the ash trees - as long as they don't try to eat them.

Residents in Ankeny, Iowa are also dealing with the looming threat of these tree-hungry pests.

"Most people have already heard the problem is here and that it doesn't mean good things," Iowa Department of Natural Resources Urban Forestry Specialist Shane Donegan told the Des Moines Register. "Instead of the info just being doom-focused, we are really trying to give people options for how they can prepare."