It takes a sparkle in the eye to attract a female mate, butterfly researchers have found.
some male animals use bright colours or intricate mating dances to
seduce females, U.S. biologists found one species of butterfly flaunts
the reflective patches on their wings during courtship.
Kendra Robertson paints the eyespot on the wing of a male butterfly, shown in inset. (Courtesy: University of Buffalo)
Biology Prof. Antonia Monteiro of the University at Buffalo investigated the evolutionary role of eyespots in Bicyclus anynana butterflies.
suspect eyespots distract predators away from a butterfly's vital
organs. The insects also have eye patterns on their inner dorsal wings,
but their purpose is unknown.
Males flicker their wings during
courtship to show off the eyespots, and females make the mating
decisions for the species, the authors note in the June 29 online issue
of the Proceedings of the Royal Society B: Biological Sciences.
Monteiro's team thought the pupils reflect ultraviolet light to catch a female's eye.
To test their idea, they painted the wings with UV-absorbing paint that did not change the colour of the limbs.
the white pupil on 50 male dorsal wings made them less desirable to
females by a ratio of two to one compared to untreated males, the team
Changes to the ventral side appeared to make no difference to the females' mating decisions.
is one of the first studies to show that such a small pattern element
really matters in female choice," Monteiro said in a release.
thought that the males flutter their wings to stimulate females
visually and to spread pheromones to her antennae. It probably looks
like a strobe-like effect to her, said study co-author Kendra
Male butterflies may lose reflectivity over time
as the scales on their wings fall off. If so, sparkly wings may signal
younger, healthier mates, the team said.