COUNTY AG NEWS

New invasive insect

The Lily Leaf Beetle is a bright red beetle in the Chrysomelid family native to Europe and Eurasia. It has been found in the eastern U.S. and has now been detected in Wisconsin.

The Lily Leaf Beetle was first found in the United States in 1992 in Cambridge, MA. Since then it has spread through New England into New York State, with one infestation in Ohio. The insect is native to Europe and Asia, and is believed to have arrived in the U.S. in a shipment of lily bulbs from Europe.

The Lily Leaf Beetle has no effective natural enemies in North America. It was first detected in Wisconsin in Marathon County in the summer of 2014. How it arrived or how long it’s been here is uncertain, but to date, its’ distribution seems to be limited to Marathon County.

The adult Lily Leaf Beetle is scarlet with a black head, antennae, legs and underside, and is ¼ to ½-inches long. It overwinters in the soil and emerges in very early spring through June. The females lay irregular strings of eggs on the undersides of lily or fritillaria leaves, up to 450 in one season. The eggs hatch in one to two weeks into orange to light green slug-like larvae that wrap themselves in their own black excrement to repel predators. After feeding for 16-24 days, they burrow into the soil and become fluorescent orange pupae that emerge in 16-22 days as red adults. There is one generation per year.

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