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Treat trees for emerald ash borer now. Here’s how.

April 9, 2018 | Jodi Baker | reliability, tips, trees
emerald ash borer

The emerald ash borer (EAB) is making quite a name for itself, and not in a good way. The invasive insect destroys ash trees in its path. Once it arrives in a region, it spreads quickly. It’s been in Nebraska since 2016, and a million trees in this state are at-risk.

EAB threatens not only the beauty of our landscape, but also the reliability of electric service. That’s because diseased trees don’t just dwindle slowly and lose leaves. The pests destroy tissue within the tree that transports water and nutrients. Weakened trunks eventually snap near the base, and trees crash down onto whatever’s nearby – including power lines.

“Our foresters have identified at least 10,000 ash trees in proximity of power lines within OPPD’s 5,000-mile service territory, alone,” said Mike Norris, a utility forester with the district. Norris is also a member of the Nebraska EAB Task Force.


Property owners with ash trees can and should take action to prevent power outages and other safety hazards caused by EAB-infested trees. The time to act is now, before the bugs come out, which is typically in May. They stay active through August.

Proximity matters

Preventative treatment is recommended if EAB has been found within 15 miles of your location. That covers most of OPPD’s service territory. You can check on your specific location by visiting the Nebraska Forest Service.

Viability of tree

A healthy tree will respond better to treatments and better handle the potential damage treatments can cause. Your tree is likely healthy if:

  • It doesn’t have insect or trunk damage
  • The tree is located where the soil is not disturbed by traffic, trenching or utility lines
  • It has a history of proper watering
  • The tree has a full canopy with lots of leaves.

If your tree is not healthy to start with, or if it is located near power lines, you may want to consider having it removed. Never attempt to cut down a tree near a power line yourself.

“Enlist the help of professionals who will contact OPPD to ensure safe access to complete this work,” Norris said.

Treatment options

A certified arborist should treat healthy trees every one to two years. Some options for trees of all sizes include: trunk injections and basal trunk sprays, soil drenches and granules, implants, bark and foliage sprays. Here’s a treatment timeline:

  • April (or fall, but not as effective) – soil drenches with imidacloprid
  • Mid-May – bark sprays with bifenthrin, cyfluthrin or permethrin
  • Mid-May through early June – soil drenches with dinotefuran; **trunk injections and implants; **basal trunk sprays with dinotefuran
  • **Applied only by professionals.

Norris recommended talking with a certified arborist to determine your best course of action. For help locating one in your area, click here.

“The time to act is now,” Norris said. “Infestations kill about 70 percent of unprotected ash trees within four years of initial discovery. So, by 2020, our landscape will likely look very different.”

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About Jodi Baker

Jodi Baker writes stories and shoots videos for The Wire. Jodi was a television news reporter before she came to work for OPPD as a media specialist in 2013. Jodi earned her degree in broadcasting from the University of Nebraska-Omaha. She's worked for news stations from her hometown of Omaha to sunny San Diego. She’s married with two bright and energetic children (a boy and a girl) and an allergy-ridden little Cairn Terrier. She and her husband enjoy catching up on some grown-up DVR time once the kiddos are asleep.

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