At first glance, you might not think these little bits of fluff could pose much of a threat. But, like Star Trek’s troublesome tribbles, hemlock woolly adelgids (Adelges tsugae) can quickly multiply and wreak havoc. When these tiny sap-sucking insects were introduced to the forests of the Northeastern United States, they lacked an effective predator and within a few decades they caused significant die-offs of eastern hemlocks (Tsuga canadensis) and Carolina hemlocks (Tsuga caroliniana) — trees that are both economically and ecologically important to eastern forests. Woolly adelgids were clearly destructive, and they were spreading, but it wasn’t clear exactly how they were spreading.

continue reading: