I’m fascinated by invasive species — meaning any living organism that is introduced to a non-native ecosystem and causes harm (harm to native species, crops, humans, property, the economy, whatever). Invasive species typically adapt to their new environment quickly and reproduce quickly as well, such that, for example, that quirky kudzu plant introduced to the US in 1876 via the Centennial Exposition in Philadelphia has become a dominant feature of the Southern US landscape:
No big deal, except that kudzu, introduced with the best of intentions to try to stop soil erosion, is a juggernaut of a plant, expanding at a rate of about 50,000 baseball fields per year. It’s hardy, and it believes strongly in its own manifest destiny, crawling ever westward and upward, smothering native plants and contributing to climate change along the way.
Many invasive species are introduced by accident. For instance, zebra mussels arrived in the US clinging to ship hulls. Lionfish appeared in the Gulf of Mexico thanks to owners of the pretty fish releasing them after buyer’s remorse. On Marion Island, mice brought in by hunters in the early 1800s prey rather horribly on sea birds (I’ll spare you any pictures, but here’s an interesting interview on the subject). Opportunists like tawny crazy ants, red fire ants, tiger mosquitos, and formosan termites came via infested shipping containers.
My favorites, though, are those introduced in “There Was an Old Lady Who Swallowed a Fly” style, to try to control another species. For instance, an invasive scale insect from Asia was introduced to try to combat European roseau (reeds, basically) in Louisiana; alas, the invasive insect species only likes to chomp on the native species of roseau, becoming a new pest. Similarly, Louisiana’s nutria problem
began in part because E.A. McIlhenny, founder of Tabasco™, hoped the rodent would chow down on water hyacinth, another invasive species causing real problems in Louisiana waterways. Spoiler alert: Nutria prefer to eat just about everything else, contributing to the loss of at least 40 square miles of Louisiana land over the past two decades. As Avocadans might recall, cane toads were introduced to Australia to prey on cane beetles. They did not.
You’d think we’d learn, but it turns out the most effective manner of fighting kudzu discovered so far is goats. Well, at least it’ll be an adorable infestation!
Have a great day, Avocados!