For some time, scientists have been sounding the alarm on the decline of various insect species due to changes in land use and how those shifts will be exacerbated by climate change. However, insects are often an afterthought in the discussion of conservation issues related to wind energy infrastructure.
A recent University of Wyoming graduate led a study that looked at the current knowledge in the relationship between wind turbines and insects -- an area of research about which little is known.
“The argument of the paper is that insects are heavily interacting with wind energy, both positively -- some insects are able to use turbines for refuge and even overwintering -- and negatively -- large numbers of insects are killed by striking turbines -- but it is not a conservation concern you often hear discussed when it comes to renewable energy, and there is still a lot we don't know about these interactions that merits study,” says Michelle Weschler, an assistant research scientist with the University of Wyoming’s Natural Wyoming Diversity Database (WYNDD). “Our paper focuses heavily on the hypothesis that insects may be attracted to turbines, which could be increasing the number that are killed by turbines and also serve to attract vertebrate wildlife to turbines, making them vulnerable to fatally striking the blades as well.”
The paper also examines the ways that turbines change habitat conditions, such as temperature, soundscape and wind speed, and how that might affect insects, she adds.
Weschler was lead author of a paper titled “Wind Energy and Insects: Reviewing the State of Knowledge and Identifying Potential Interactions” that was published Oct. 14 in PeerJ Life & Environment, a peer-reviewed, open access journal that publishes primary research and reviews in biology, life sciences, environmental sciences and medicine.
Lusha Tronstad, lead invertebrate zoologist with UW’s Wyoming Natural Diversity Database, was the second author on the paper and Weschler’s faculty adviser.
In 2023, the wind industry hit a milestone of one terawatt of installed capacity globally, according to the paper. That amount of wind energy capacity is expected to double within the next decade as billions of dollars are invested annually in new wind turbine projects. As a result, wildlife mortality is a primary concern.
Turbine placement, color, shape, heat output and lighting are possible attractants of insects to turbines, according to the paper.
“We examined a few of these options as potential attractants. Right now, the most evidence exists for color,” Weschler says. “There have been two studies that found evidence for increased insect attraction to the bright white paint used on most turbines globally compared to other colors.”
Additionally, she says there is reason to believe that insects may be attracted to the shape and placement of turbines; that is, the wind turbines may be acting as markers on the landscape that could be useful congregation points for insects.
“Turbines also give off heat, which definitely attracts some insects to bask on the towers. Beetles and flies, specifically, have been found to rest on towers despite the increased risk for predation,” Weschler says. “There is certainly potential for light to be an attractant. By law, turbines must have lights that flash at night, but we have yet to see solid evidence for attraction due to that, and the type of lights that are industry-standard -- red and LEDs -- are usually less attractive than other types of light.”
While Weschler says it’s “currently impossible to identify the risk to specific species,” the paper proposes methods for extrapolating this information, such as DNA barcoding of debris scraped or washed from turbine blades. However, the answer to risk factors will be different depending on the location of a wind energy facility.
The paper does include a table, which is offered as supplemental information and examines the vulnerability of different insect orders based on factors that include the maximum altitude at which they've been surveyed and responses to stimuli such as light, heat, wind and sound, and their flight and migration behavior, Weschler says. Based on this assessment, the table suggests that moths and butterflies, beetles, flies and true bugs may be the most vulnerable to striking turbines.
“Members of these orders engage in high-altitude migrations, swarming and hill-topping behavior,” Weschler says. “Additionally, some species within these orders are acutely heat-sensitive and have been found basking on turbine towers.”
Weschler hopes the study’s results will be useful for researchers who are interested in insect conservation, as well as land managers and wind energy operators.
“Insects are increasingly being listed under the Endangered Species Act in the United States, and there is global concern from entomologists regarding large-scale insect decline over the past decades,” she says. “Wind energy and renewable energy projects, in general, are rapidly growing, so I think the link between these is worth considering on a conservation level. Hopefully, this will inspire further studies and investigation so that we can fully understand the scope of the issue.”
The project’s paper was a revised and peer-reviewed version of Weschler’s master's thesis. Weschler received her master’s degree in zoology and physiology from UW in August 2023. Before coming to UW for graduate school, Weschler was living in her hometown of Orlando, Fla, and working remotely for the University of Florida’s Honey Bee Research and Extension Laboratory.
“Lusha has led the charge on a few other studies investigating aspects of wind energy effects on insects. She secured funding from the U.S. Fish and Wildlife Service for a master’s project, wherein the final product was a literature review on the subject,” Weschler says. “I had a background in both entomological field work and synthesizing information from existing literature for classes on apiculture, so I thought the opportunity sounded like a perfect fit.”
Weschler was awarded the Great Plains Cooperative Ecosystem Studies Unit Graduate Student Award for her graduate research, Tronstad says.
“Her work is very novel. Wildlife research has been limited to birds, bats and ungulates, and virtually nothing was known about interactions between insects and wind energy. Michelle’s work is not currently available in the literature in any form,” Tronstad says. “We hope that her thesis work creates discussion in wind energy and wildlife sectors. Michelle has supplied the background information on insects and wind energy, and our hope is that her foundation will lead to solutions that will conserve wildlife while also leading to more energy produced by turbines.”
The study was funded by the U.S. Fish and Wildlife Service and the Bureau of Land Management.