By Mariam Taleb, Ph.D.
If it feels like new invasive species are showing up faster and faster, the research says you’re right, and that there’s no sign it will slow down soon, according to Nature Communications. Biological invasions can feel like an existential threat, and often leave us anxious and ready for action. In some ways, that anxiety is warranted — invasive pests can upend our farming and gardening systems and dramatically change the landscapes we used to know so well. There is even research that says that biological invasion isn’t just driven by the environmental crises we’re facing — biodiversity and habitat loss, and even climate change — some biological invasions might even contribute to those crises, as research in the journal Biological Invasions has often found.
Sometimes, though, our anxieties and efforts end up misplaced, often because we — scientists, journalists, politicians and our communities — aren’t good at defining and describing biological invasions. I think biological invasions could use some reframing so we can all be better at reading news about them, and know when not to panic about the next big invasion.
We tend to think of biological invasion as a thing that’s happening to us here and now, but if we’re genuinely concerned about environmental damage on our ancient and shared planet, it’s important to take a broader view. For example, biological invasion is much older than we usually think of. Common “weeds” like plantain, Queen Anne’s lace and mugwort were intentionally brought to the Americas by early white European settlers as easy-to-grow food sources and traditional medicine. We also forget, for example, that biological invasions are reciprocal — we export as many or more species as we import! (I’ll come back to this.)
So, let’s reframe. The first step of broadening the view of biological invasion is to clarify its definition. Biological invasion is a process by which populations of species are transported by humans (intentionally or unintentionally) into new habitats that they then survive and thrive in.
Biological invasion is not the gradual shifting of geographic species ranges as a result of climate change (e.g., pests that are new to Maine as winters get milder). Biological invasion is not a binary (invasive/not, alien/native) but instead is a multi-step process with tons of gray space along the way. Organisms have to survive travel, escape into the environment, survive in that environment, and reproduce at or above the rate of replacement in that environment! That means the vast majority of potential invasions are thwarted before you ever hear about them.
Where we really get tripped up, though, is when we forget or ignore that biological invasion is definitionally human-mediated. We bring all of our global human messy complexity and biases to the table. That means we tend to focus on invasive species for very anthropocentric reasons, that we understand invasive species in very human terms, and that biological invasions are entangled with and influenced by issues of global trade and politics.
For example, we often use political borders between states and countries as a shorthand for where and how invasive species are moving through our landscapes, but that often leads experts and laypeople alike to place too much weight on those political borders, as if invasive species know or care about them. Invasive species instead are more bound by ecoregions, such as the mixed wood plains and Atlantic highlands of Maine, which stretch in a band from eastern Minnesota to the Atlantic coast and from northern Pennsylvania to the southeastern provinces of Canada (categorized in “Level II Ecoregions” by the Environmental Protection Agency). Once an invasive species has established in an ecoregion, it should be assumed that it cannot be eradicated from that ecoregion and that the goal of slowing its spread is to offer researchers more time to develop mitigation tactics.
Another funny effect of thinking about invasive species in terms of political borders is that it can lead media, researchers and government agencies to focus their energies on invasive species from countries we are politically or socially concerned with. One example of this that’s been questioned in the years since is the mania around the Asian giant hornet, or the “murder hornet” as The New York Times seemingly dubbed it in May of 2020, two months into a pandemic that had originated in East Asia. That mania turned out to be dangerous to us and to native pollinators. Already in a heightened state of anxiety, concerned folks started killing first and identifying second. According to an article in National Geographic, swaths of native pollinators were killed by crushing, the (mis)use of toxic pesticides and even fire, just in case those insects might have been Asian giant hornets.
We’re human-centric in little ways, too. Research in Trends in Ecology and Evolution has found that we have a bias against invasive species that are large enough to see with the naked eye, and that inhabit the same microhabitats that we do (e.g., built structures, urban parks or lawns). We also tend to worry most about invasive species that we think might threaten our economic goals but ignore invasive species that we can monetize, according to research in Biological Invasions. Honey bees are native to Europe, for example, and are known to be a key driver of native bee decline in the Americas. Yet honey bees are celebrated and are often the focus of “save the bees” campaigns, as has been pointed out in Scientific American. Our cultural aesthetics also dictate our degree of concern about invasive species. Common lawn grasses are almost all native to Eurasia (including Kentucky bluegrass!) and often are to blame for displacing native plant communities.
Perhaps the most dangerous way that we are human-centric in our thinking about invasive species is our tendency to describe them in human terms, often with disturbing undertones. Anthropomorphism is defined as the very human habit of ascribing human emotions, behavior and intent to animals. Invasive species are often described with very emotional terms — think “murder” hornets and “killer” bees. They are described in terms of their productivity — “lazy,” “helpful,” “busy.” They are sometimes described as having goals — they are “trying” to spread. But none of this is true — even if one were to argue that animals do have emotions and intents, it would still be true that we do not know what they are.
Carlos Eduardo Jones; CC BY 2.0, cropped from original
Unfortunately, the danger of anthropomorphism is that once we have applied “humanness” to plants and insects, we also apply our biases about our fellow humans — and it shows. “Africanized” honey bees are hybrids between European honeybees and the East African lowland honey bee. They first came to the Americas by way of Brazil in the mid-20th century. Since then, there have been periodic panics about the possibility of Africanized honey bees threatening our way of life. Over the years, in news articles and research papers alike, these bees have been described as “killers,” which are “naturally more violent.” They’ve been described as “lazy” and “unproductive.” Concerns have been raised that Africanized honey bees will sneak into European hives, breed with those bees, and decimate honey production by passing on such undesirable traits to their offspring. In this language we can see racial undertones applied to animals so distanced from us biologically that they do not even have spines. (As an aside, beekeepers who’ve found Africanized honey bees in their hives have reported that while honey production did temporarily dip, that is only because they had to slightly alter their management practices to suit these new bees.)
It’s not all that surprising to find this language embedded in discussions on biological invasion. It is frightening, and it does conceptually lend itself to all of the unkind ways we talk and worry about immigration and other societal changes. Invasion ecology is also a relatively young field and still has a lot of work to do to escape some of its early influences — including “purity” language that was borrowed from ecologists in Nazi Germany, as even one of the most avid defenders of invasion ecology admitted in an article in Biological Invasions.
Our collective ignorance of the ways biological invasion is influenced by social, political and economic forces also has much more far-reaching impacts. In my research, I found a lot of good evidence that countries, like the United States, that have more global political and economic power both indirectly and directly make it much harder for poorer and less powerful countries to protect themselves environmentally or through trade policy against biological invasion. At the same time, more powerful countries are able to hold poorer countries to incredibly high standards in sanitizing their exports. As a result, the United States and other wealthy countries are likely exporting far more invasive species than they import.
So, what does any of this have to do with you, here in Maine, worrying about the next invasive species to roll through your garden, farm or woods? Firstly, all this means that the information you receive about invasive species is often sensationalized. When reading news articles about invasive species, I encourage you to pay attention to descriptions of species that might be anthropomorphized for dramatic flair. Consider whether the newest invasive species is being conflated with current events in our political and economic world. And watch out for headlines that are more dramatic than their articles! Journalists write articles to inform their audience, but editors write headlines to entice their audience. Now that you know more about the science of biological invasion, pay close attention to the word choice in articles and notices about new invasive species. For example, watch out for the word “detected.” Finding invasive species is notoriously difficult, so where a species is “detected” is not the same thing as where it actually is. Pay attention, also, to what the experts say are the actual potential impacts to our environment and lives. Will they affect agriculture and gardens? Forests? Are researchers even certain yet about the types and severity of impacts we might see?
Most importantly, try to keep a broader view in mind when you are deciding how you will help protect your local ecological community from the next invasive species. Killing members of invasive species can be satisfying, especially in a time where we often feel powerless to do much about big environmental issues. However, it’s important that we don’t do so at the expense of native species and native communities or soil health!
Remember that invasive organisms are still organisms — be cautious about what tactics you use to combat them, and don’t seek options that are unnecessarily cruel. Choose management options that have been recommended by experts. If there aren’t recommendations yet, don’t use methods you wouldn’t already use (such as lighting your yard on fire!). Pay attention to what researchers are asking for. Usually, they ask for help with detection. Consider practicing your plant and insect identification skills so you’ll be ready to accurately identify the next big thing. Pay attention to your language when you talk about invasive species, and question whether it’s the most scientifically accurate way to discuss that species. Support and nourish your native species and habitats! And when all else fails, call an expert — we’re all happy to get the chance to tell you what we know, what we think, and what’s got us stumped.
Mariam Taleb lives in Westbrook, Maine, and works as an agricultural service provider. She holds a Ph.D. in entomology and international ag and development from Penn State. She studied the socio-ecology of invasive insects.
This article was originally published in the summer 2024 issue of The Maine Organic Farmer & Gardener. Browse the archives for free content on organic agriculture and sustainable living practices. Subscribe to the publication by becoming a member!
