Study: Invasive Beetle Posing Bigger Threat Than First Thought

Yellow Margined Leaf Beetle

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A new University of Florida study suggests the invasive yellowmargined leaf beetle’s cold tolerance could help it spread much further north than its current range. Researchers report in the December 2012 issue of Annals of the Entomological Society of America that the beetle’s eggs can withstand prolonged periods at 32°F. That means the insect might survive in Kansas, Illinois, Missouri, Kentucky, and Virginia, says UF/IFAS entomologist and associate professor Ron Cave.

Native to southern South America, the yellowmargined leaf beetle was first reported in the U.S. in 1945 and is now found in Texas, Louisiana, Mississippi, Alabama, Florida, Georgia, and South Carolina. Larvae and adults feed on the leaves of many cole crops, with turnips being the preferred host. The pest also poses a threat to mustard, radish, collard, watercress, bok choy, and napa cabbage.

In conventional production, the beetle is susceptible to foliar insecticides. In addition, UF/IFAS researchers are investigating several biocontrol options, including the spined soldier bug, green lacewing, trap crops, and fungi that attack the beetle’s larvae.

In the meantime, Cave advises all cole crop producers to scout their fields thoroughly in early fall, so that infestations can be addressed before the beetles become too numerous.