Invasive Kudzu Bugs May Pose Greater Threat Than Previously Thought

www.ScienceDaily.com
April 15, 2013

The invasive kudzu bug has the potential to be a major agricultural pest, causing significant damage to economically important soybean crops. Conventional wisdom has held that the insect pests will be limited to areas in the southern United States, but new research from North Carolina State University shows that they may be able to expand into other parts of the country.

Kudzu bugs (Megacopta cribraria) are native to Asia, and were first detected in the U.S. in Georgia in 2009. They have since expanded their territory as far north as Virginia. The bugs have an interesting life cycle, which has been thought to be a limiting factor on far they can spread.

Eggs laid in the spring hatch into a first generation, which we'll call "Generation A." The immature bugs of Generation A normally feed on kudzu plants until they reach adulthood, when they have been known to move into commercial soybean fields. These mature adults lay eggs that hatch into Generation B during the summer months. Generation B kudzu bugs can feed on soybean crops during both their immature and adult life stages, causing significant crop damage. Because the immature Generation A kudzu bugs have only been seen to feed on kudzu, researchers thought that the pest would not be able to migrate to northern and western parts of the United States, where kudzu doesn't grow. But now it's not so clear. ...

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Invasive species may be key to understanding death of hundreds of loons

by Dan Kraker, Minnesota Public Radio

DULUTH, Minn. — Spring is in the air, with daylight savings taking effect on Sunday, and loons will begin their migration back to the north woods in less than a month.
         
Loons, of course, are a cultural and natural icon, not only in Minnesota but across the Great Lakes states. But last fall, nearly 900 loons died while migrating south across Lake Michigan, probably more. And it's likely at least some were from Minnesota.
         
Scientists are not sure what killed the loons, but they suspect that invasive species may be to blame.

In October, Lynette Grimes was hiking toward Lake Michigan at Sleeping Bear Dunes National Lakeshore, outside Traverse City, Mich. The 52-year-old from the nearby town of Benzonia has walked the beaches there for years. But she wasn't prepared for what she saw. ...

The scientists offered an idea about what might have happened: Invasive zebra and quagga mussels filter the water so it's incredibly clear, allowing an algae called cladophora to grow in huge amounts. Big storms churn up the algae, which settles to the lake bottom and rots. That creates an environment without any oxygen, an ideal home for bacteria that produces a deadly toxin called Type E botulism. That botulism is ingested by invertebrates, tiny worms and freshwater shrimp. And then it works its way up the food chain. They are eaten by fish, including the invasive round goby, which are then eaten by diving birds like loons. ...

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Image: J.M. Kosciw