The Cinnabar Moth Has Been Actively Introduced To Regions As A Tool For Controlling?
The case of the cinnabar moth in North America is a curious one in two ways. First, the moths and their larvae—unlike many of their cousins—aren’t destructive to things like fabrics or crops and are, in fact, actively sought out. Second, though it’s not native to North America, you can hardly call it an invasive species because farmers and municipalities have actively courted the fiery-colored little moths by releasing thousands upon thousands of adults.
Why import a moth species? Cinnabar moth larvae love ragwort. In fact, ragwort is one of only two plants (the other being groundsel) the larvae feed on. Female moths lay their eggs in batches of 30 to 60 on the underside of ragwort leaves and, when the eggs hatch, the resulting caterpillars devour the host plant in a quest to gather the poisonous alkaloids in the plant to make themselves entirely unpalatable to predators.
The life cycle of the moths then, has the direct benefit of removing ragwort from grazing lands where it would otherwise serve as a tasty and colorful, yet deadly treat for cattle, horses, and other grazing livestock.
The best part about using the cinnabar moths for ragwort control is that the moths depend entirely upon the ragwort for survival. Eventually, should the moths be successful at entirely eradicating the ragwort, they’ll have eaten themselves right out of a home. With this neat, albeit fatal end game, we won’t have to later import a creature that loves eating cinnabar moths in some sort of ecological arms race.
Image courtesy of Quarti/Wikimedia.