This Nasty Pest Costs Midwest States Like IA, WI, & IL Millions Each Year

Football season is here, the leaves will soon be changing (if they haven't already), and every woman alive is scrambling for a thing called pumpkin spice latte. Yes, the crisp season is pretty much here which means bonfires and wood-cutting season is here too.

I used to do a lot of wood cutting when I was a kid. Our old farmhouse was heated by a massive wood-burning stove. That was back in the Nineties, before we had issues with an invasive tree killer; enter the Emerald Ash Borer (EAB). This Asiatic pest was first identified in the United States in Michigan in 2002.  It is believed that the beetles actually first arrived in the early Nineties and were killing trees by 1998. From there they spread, and fairly rapidly, infected Iowa trees by 2010.

When EAB was first discovered, quarantines were placed to try to stop and slow the spread of the insect by restricting the movement of firewood and ash tree materials. In January 2021, the USDA decided to end its "quarantine" in favor of directing its efforts to research and release biological control agents to manage EAB populations.

The impact of these six-legged nasties is significant; according to reports, More than 99% of ash trees that have been attacked have been killed. That's less than 1 in 1,000 trees that survive. The economic losses associated with Emerald Ash Borer infestations are significant, according to the U.S. Forest Service.

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• The 8 billion ash trees in U.S. forests are worth an estimated $282 billion.
• Timber from ash trees is valued at $25 billion per year in the eastern US.
• Ashwood is used to make tool handles, baseball bats, furniture, cabinetry, basketry, solid wood packing materials, pulp, and paper.

How do they control Emerald Ash Borer Populations?

Currently in the US, EAB-resistant ash trees are being looked into, but it could take years to regrow infected and dead growth areas across the nation. Instead, scientists have looked at biological agents to do the dirty work of eliminating and slowing the spread of the emerald ash borer. Currently, one species of egg parasite has been released, which according to US scientists, will not become an invasive pest.

Oobius agrili is a non-stinging wasp that uses emerald ash borer eggs as fodder for its young. The female wasp lays its eggs in the eggs of an EAB, and the wasp larva will eat the EAB eggs. So far, three species of larval parasites (Tetrastichus planipennisi, Spathius agrili, and Spathius galinae) have also been released. The females of these wasps lay their eggs on the outside of EAB larva or inside the EAB larva and after the wasp larva hatch, they eat the EAB larva. Since 2007, over 5 million parasitoid wasps have been released. In some areas where the wasps are released, up to 80% of the EAB larva examined have been parasitized by these wasps.

How can I help prevent the spread of the Emerald Ash Borer?

Firstly, the latest campaign can be found here, with the basic premise being not to move firewood. The slogan, "buy it where you burn it" needs to become a top-of-mind mantra for not only campers and wood burners, but for anyone in the wood and forestry industry. Although it is not illegal to transport firewood within Iowa, the DNR encourages you to avoid moving firewood over great distances. In Michigan, Individuals or businesses found violating the state's EAB quarantines are subject to fines ranging from $1,000 to $250,000 and jail time of up to five years for moving regulated ash materials, including firewood. In Illinois, the movement of firewood is restricted. In Wisconsin, a permanent rule prohibits the entry of uncertified firewood onto state DNR-owned properties if it originated more than 10 miles from the property. There are also multiple treatment options that can save ash trees from EAB infestations.

• Soil-applied treatments, applied annually, can treat trees no more than 15 inches in diameter.
• Trunk-injection treatments, treat trees with a diameter greater than 15 inches and need to be reapplied every two years.
• Systemic basal trunk sprays are sprayed annually to treat the trees’ vascular system.

For more information on the prevention and spread of the emerald ash borer visit the Iowa DNR invasive pest page. Additional resources on treatment plans and pest eradication resources can be found at the Iowa Department of Agriculture & Land Stewardship website.