Children in Michigan and growing parts of the U.S. are witnessing the death of a species, ash trees. A local conservation educator wrote about how even his fifth-grade students could spot the drill hole-shaped indications of an emerald ash borer (EAB) infestation. Roger Mech, from the Michigan Department of Natural Resources, ominously foreshadowed in 2015 that “billions of dollars [will be lost] as EAB continues to spread.”
Now, new detailed research has found that individual county-level earnings in the most vulnerable industries drop by as much as 4% in the years after EAB has been detected. This study on the economic effects of county-level EAB detection, spearheaded by University of New Mexico economics professor, Benjamin A. Jones, found there to be significant negative impacts on the community’s labor market and economy in the years following infestation.
The emerald ash borer is an invasive species, native to Asia, which feasts on ash trees. The larvae of EAB burrow into the ash tree’s inner bark layer siphoning off the host’s nutrient-rich sap. An adult EAB is about half an inch long and a quarter of an inch wide with metallic, emerald green outer shells and a red-copper abdomen. Although the small shape and Christmas-colored exterior of EAB may seem almost inviting, there are massive efforts to control and regulate the spread of this ravenous invasive species, and for a good reason.
The EAB has emerald green elytra (tough outer shell wings that protect the flying wings below). Credit: Ecological Landscape Alliance
The death of ash trees even changes temperature and air quality. Temperatures increase when ash trees disappear because there are fewer shaded areas and sources of photosynthesis. Trees also act as natural air purifiers, cleaning away toxic pollutants, and improving air quality. The United States Department of Agriculture (USDA) also reports that ash trees represent 10-40% of tree cover in urban communities so the death of these trees could leave portions of already nature-starved cities without wildlife.
County-level research confirmed EAB’s devastating economic effects, as well. Earnings in every sector dropped by an average of 1% in the years following an EAB detection, with a near 4% drop seen in the manufacturing industry which heavily relies on wood and paper products. Workers retired at higher rates after EAB detection due to job loss and EAB detection lowered average county-level per capita earnings by $174.14. That might not sound like much, but over the ten year period investigated, EAB cost these counties a whopping $11.8 billion.
The relationship between EAB detection and these findings are extremely clear because the drop in earnings follows the EAB destruction cycle. Initial detection of EAB did not constitute an immediate economic loss, just as one EAB sighting does not immediately kill an entire forest. After a few years, when almost all of the ash trees in the communities were damaged or dead, the economic impact reached its peak while businesses shut down or moved and jobs were lost.
The spread of EAB by year first detected. Credit: Benjamin A. Jones, Figure 1 in study
The EAB is almost impossible to contain. The pest equips a killer combination of high reproduction rates and fast rates of spread. The latter is usually facilitated by humans, unintentionally helping them cover huge swaths of the United States as they hitch rides on our vehicles and in our luggage. Invasive species, such as EAB, that live on trees are most commonly transported through the timber industry and the delivery of goods on wooden pallets or crates. Since 2000, when EAB arrived in Michigan, this little insect has been rapidly spreading across the country. In the past four years has it reached parts of the east coast such as Massachusetts, Connecticut, Pennsylvania, and New Jersey.
Most recent EAB quarantine map from October 1st, 2020. Credit: Emerald Ash Borer Information Network
The USDA is taking several steps to limit the spread of EAB. The most significant of these is the implementation of an EAB quarantine zone which limits shipments of timber and other wood-based supplies from infected areas to non-infected areas without a permit. This means that a timber company based out of New Hampshire would require a permit to move its products into neighboring Maine. This is one of the common techniques used in the prevention of the spread of invasive species, along with educational training combined with sighting and reporting methods.
This research brings forest-attacking invasive insects to the forefront of environmental issues. These invasive species require and deserve to be recognized by other agencies as a credible threat to American livelihood. With the increased globalization of trade, the issue of invasive species has become an even greater threat to American economic well-being. The combination of economic and environmental damage that invasive insects cause to communities across the country, as well as the rapid rate at which these damages are spreading, should be a wake-up call to policymakers. We must address the issue of invasive species.