Japanese researchers reveal female butterfly’s sex avoidance secret

Researchers in Japan have discovered the sex avoidance secret of a colorful female Japanese butterfly.

The female small copper butterfly only mates once in her life — and then shuts her wings “to avoid sexual harassment” and the persistent mating attempts of males who won’t take the hint.

In “Observations of the Small Copper Butterfly,” lead scientist Jun-Ya Ide showed that the female butterflies that have already mated close their wings when males of their own species fly by. By doing this, they hide their beautiful orange and black wing patterns and make themselves less recognizable to the males.

“Closing their wings makes them less visible, helping them avoid communication with their own species. We figured they were trying to avoid sexual harassment by males," Ide, an associate professor at Kurume Institute of Technology in Fukuoka, told Reuters.

The scientists describe their findings in the journal Ethology, the BBC reports.

In a test, Ide and other researchers brought a model of a male small copper butterfly near a group of females to see their reactions. The researchers found that virgin females that had yet to mate kept their wings wide open, but those that had already mated quickly shut them.

Ide said this trick not only deters unwanted male suitors, but it also protects the delicate female butterflies from having to flee from an amorous male in hot pursuit.

"I concluded that, since females don't need more copulations, they close their wings to conceal themselves," Ide told the BBC.

On the other hand, virgin females that want to mate "keep their wings open to be conspicuous."