LISLE, Ill. (CBS) — The emerald ash borer and the drought this summer are teaming up to give a one-two punch to ash trees in the area.

As WBBM Newsradio’s Bernie Tafoya reports, if you have an ash tree on your property, you might want to keep a close watch on it. If it becomes infected with the emerald ash borer, Illinois Forest Pest Outreach Coordinator Andi Dierich of the Morton Arboretum says the insect and the drought will result in killing the tree faster by “knocking out (ash trees’) ability to transport water up and down the trees.”

LISTEN: WBBM Newsradio’s Bernie Tafoya reports

Dierich also says towns that have spent tens of thousands of dollars to replace infected ash trees have to spend more money now to keep them alive by regularly watering baby trees.

“A lot of times, the roots haven’t had time to establish into the ground, so you’re preventing it from getting any water at all and growing, essentially, so you might end up with a dead tree at the end of the summer if you don’t water it,” Dierich said.

Dierich’s rule of thumb for tree watering is to administer 5 gallons of water for every inch in diameter of tree.

Dierich says because the emerald ash borer is already established in the Chicago area, infestations are more pronounced because the trees are already under stress with the drought.

According to the Daily Herald, towns such as St. Charles are asking residents to chip in by watering parkway trees themselves. Otherwise, the municipalities will have to do it or pay to have it done, costing taxpayers even more.

The emerald ash borer is an insect native to Asia which arrived in the U.S. in the 1990s. Ash borer larvae kill ash trees by consuming trunk bark, the U.S. Forest Service explains.

The insect was first spotted in Michigan in 2003, and since then has made its way across Illinois, including many Chicago suburbs.

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