Poor Plant Defenses Promote Invasive Beetle's Success

Susceptibility of the North American viburnums, the common woody shrubs found in gardens and forests to viburnum leaf beetle (Pyrrhalta viburni) has been a puzzle to entomologists. Cornell University researchers believe that the beetle was able to successfully invade the North American plant species because of their inherent lack of disease resistance mechanism, compared to related South American, Asian, and European species. The paper  which examines the relationship between the shrub and the beetle was published  in the April 11 issue of journal Proceedings of the National Academy of Sciences.

"North American viburnum species have not evolved with a leaf beetle," said Anurag Agrawal, professor of ecology and evolutionary biology, and the paper's senior author. He added that, "In the absence of beetle pests, the North American species have evolved low levels of defense."

The team studied evolutionary relatedness among groups of organisms using molecular sequencing data and morphology.

For more on the news, see http://www.news.cornell.edu/stories/April11/ViburnumBeetle.html.