When certain caterpillars are raised in warm, moist conditions they grow into what some would consider traditional roles — males pursuing demure females. But new research has found that when they are raised in dry, cool conditions, it's the ladies that become aggressive adults, actively courting the guys. Researchers led by Kathleen L. Prudic of Yale University report their findings in Friday's edition of the journal Science. They studied Bicyclus anynana, known as the squinting bush brown butterfly because of the eye-like patterns on their wings.
What are these butterflies doing?
BBC - Earth - Male butterflies in sperm war
She has a special digestive organ just for this purpose. This sperm-hungry organ is called the bursa copulatrix. And this starts to explain why their sex organs are so complicated. The male butterflies, like many other insects, deliver their sperm inside a package called a spermatophore. That means a butterfly like the cabbage white benefits from mating with many males.
BBC Sport (International version)
British Broadcasting Corporation Home. Male and female butterflies switch courting roles depending on the season they were born in, say scientists. Squinting bush brown butterflies use reflective "eye spots" on their wings to attract potential mates. Males born in the wet season beat their wings to flash their spots but in the dry season females grow brighter spots instead and take the lead.
Butterflies Mating But First the Courtship. Some males, such as those of the American lady Vanessa virginiensis and the Gray hairstreak Strymon melinus perch on an open branch and wait for their lady love to pass by. Other males, such as those of the Tiger swallowtail Papilio glaucus and the Spring azure Celastrina ladon , actively patrol an area, searching for a receptive gal. When the male butterfly recognizes a female of his own species, he quickly pursues her and begins the rituals of courtship. You may think butterfly dances are acts of aggression, as males attempt to drive one another away.