The wriggling larva would one day metamorphose into the red coffee-borer moth, an invasive species that damages many plants. It hasn’t yet infested the United States — but here it was, on a cloudy morning in early 2023, burrowing into the trunk of an American oak tree.
Fortunately, that particular oak tree was growing in China, in what scientists call a “sentinel garden.”
These gardens, scattered around the world, are plots of foreign trees that researchers closely monitor to figure out what local bugs and diseases can damage them. The goal is to learn as much as possible about these potential threats before they cross the ocean and become a problem at home.
“We send our trees overseas to see what bugs chew them up,” said Jiri Hulcr, a professor of entomology at the University of Florida, who is leading one of these projects.
Thousands of nonnative insects and plant diseases have found their way to the United States, often hitchhiking in on imported goods. As warming temperatures make it possible for species to survive in new places and global trade continues to expand, the spread of invasive species is expected to grow.
Many of these outsiders prove harmless, but some go on to ravage citrus groves, soybean fields and forests.