By Susan Milius
A common male butterfly deploys chemical weapons to keep rivals away from females—a great example of cooperation between the sexes that goes sour, says a team of scientists in Sweden.
Among green-veined white butterflies, Pieris napi, a male laces his sperm packages with methyl salicylate, report Johan Andersson of Stockholm University and his colleagues. This is the first time researchers have identified a chemical that serves as a butterfly anti-aphrodisiac, Andersson notes.
Females reeking of the stuff repulse males within seconds, the researchers report in the July 7 Proceedings of the Royal Society Of London B.