By Susan Milius
In a new twist on invasive-species biology, a North American insect is menacing Tahitian ecosystems by getting itself killed and proving surprisingly toxic to its predators.
The invader is a half-inch–long leafhopper called the glassy-winged sharpshooter (Homalodisca coagulata). It’s native to the southeastern United States and northern Mexico, but it reached California in the 1980s. It’s a strong flyer and has proved an unusually fast spreader of pathogens such as those for phony peach disease or for Pierce’s disease, which can kill a grapevine in 2 years.