September 25, 2009

Antenna key to Monarchs finding Mexico

Monarch butterflies locate their winter home in Mexico through a key mechanism in their antennae, scientists in Massachusetts said.

Scientists have long known that butterfly antennae can detect odors, wind direction and vibration, said Dr. Steven Reppert, chair of neurobiology at the University of Massachusetts Medical School.

But its role in precise orientation over the course of butterfly migration is an intriguing new discovery, one that may spark a new line of investigation into neural connections between the antennae and the sun compass, and navigation mechanisms in other insects, Reppert said.

Monarchs that had their antennae removed or painted black by Reppert and his team could not determine which way was south. When the team used clear paint, however, the Monarchs flew south, indicating the antenna's reading of light was key to navigation, Reppert said in the journal Science.