DES MOINES, Iowa (KCAU) — The emerald ash borer (EAB) has been found in Ida and Sioux Counties, according to the Iowa State University Extension and Outreach.

The Agriculture and Natural Resources officials said that larvae were removed from ash trees in Galva and Sioux Center by an Iowa Department of Agriculture and Land Stewardship employee. The larvae were then confirmed by the USDA.

With the new discovery, the pest, an invasive insect from Asia, has now been confirmed in all but 13 of Iowa’s 99 counties since its original detection in 2010.

Confirmed Emerald Ash Borer locations in Iowa

While full-grown EAB beetles will cause little damage by feeding on ash leaves, the larvae will feed on the inner bark of the trees. The larval feeding will cause cumulative damage by cutting off the tree’s ability to transport water and nutrients, eventually killing the trees within two to four years.

People may find an indication of an infestation if there is canopy thinning, leafy sprouts shooting from the trunk or main branches, serpentine (“S”-shaped) galleries under the bark, bark splitting, woodpecker damage, and 1/8-inch D-shaped exit holes.

FILE – In this Oct. 26, 2011 file photo, forester Jeff Wiegert, of the New York State Department of Environmental Conservation, points out the markings left from emerald ash borer larvae on an ash tree at Esopus Bend Nature Preserve in Saugerties, N.Y. (AP Photo/Mike Groll, File)

EAB can travel locally by natural means, but the long-distance spread of the insect is believed to be to people moving infested items, like firewood. As such, officials ask people to use firewood locally sourced from where it will be burned.

Ash trees within 15 miles of a known infestation are considered at risk. People can wait and see what happens to their trees, move ash trees and place them with other species, or use preventative insecticide treatments. Insecticides will work best on ash trees that are actively growing. The best time to treat for EAB is from mid-April to mid-May.

For more information on EAB, you can visit iowatreepests.com.