MARION, Ill. — An invasive beetle that has destroyed an estimated 250 million ash trees throughout the United States has been discovered in 14 additional Illinois counties in recent months, according to state agriculture officials.

The expansion means the emerald ash borer (EAB) is now located in more than half of the state’s 102 counties, with nearly two-thirds of Illinois now marked as a quarantine zone intended to help stop the further spread of EAB.

“The quarantine boundaries obviously will have to be amended to include the new detections in Logan, Menard, Perry, Sangamon and Williamson counties, as well as two other counties outside the quarantine, Peoria and Tazewell, where EAB was detected for the first time,” said Warren Goetsch, the bureau chief of environmental programs for the Illinois Department of Agriculture (IDOA).

“We will do that after all of our findings are in, which should be by November.”

The latest findings, including the first in the far southern Illinois counties of Perry and Williamson, were made thanks to purple traps set up throughout the state and routinely checked by IDOA workers as well as other local forestry experts, Goetsch said.

The beetle is distinctive in its color, metallic green, but it is less than an inch in size and sometimes difficult to detect, he said. The first noticeable signs are D-shaped holes in the bark of the trunk or branches of ash trees.

After several months, the effect of the invasion starts to become easily visible, including the thinning and yellowing of leaves, Goetsch said. Anyone who suspects an ash tree has been infested should contact their county extension office, their village forester or the IDOA.

The EAB is native to Asia, but was first detected in the Detroit area in 2002. Its larvae burrow into the bark of ash trees, causing the trees to starve and die. The new counties where the EAB has been found already are putting quarantine restrictions into place, which primarily means not moving any firewood across county lines or any parts of ash trees, including bark, limbs or branches.

Scott Schirmer, EAB program manager for the IDOA, encourages local jurisdictions to spread the word about EAB.

“Residents, businesses and municipalities should familiarize themselves with the regulations in anticipation of being included in the quarantine,” Schirmer said. “I would recommend they study management options, as well to help establish plans and budgets for addressing their infestations.”

EAB findings recently occurred in Logan County, Menard County, Sangamon County and the southern Illinois counties of Williamson and Perry. For more information, visit the IDOA’s website regarding the EAB at www. IllinoisEAB.com