The Role of Light in Butterfly Mating

From the Discovery Channel, Provided by Don Davis

An interesting item was carried on the Discovery Channel concerning butterflies and presented by Dr. Richard Wassersug. Japanese scientist were attempting to discover what mechanisms facilitated the mating of butterflies.

They discovered that males have light receptors at the end of their abdomens connected to their sexual organs. When these photo receptors are darkened, it is time to transfer sperm to the female.

During their experiments, they microcauterized and also painted over the light receptors. In these cases, reproductive success was cut in half. When painted over with clear paint, mating was successful. The butterflies also have mechanical/tactile receptors. The females also have light receptors, but these do not appear to have a role in copulation. Perhaps they play a roll in egg laying. Testing will have to be done. Moths do not have these photo receptors.