How do butterflies/moths spread their wings after emerging?
The process of a butterfly emerging from its chrysalis is called eclosion. Eclosion is controlled by hormones. These hormones are released to soften the chrysalis and to trigger the central nervous system begin the movements needed to complete the emergence process. If you look closely at a chrysalis you can see where the eyes and legs are beneath the hard surface. After the chrysalis has been softened and often become transparent the butterfly will push through first with its legs also removing the triangular piece covering its eyes and proboscis. The butterfly then crawls the rest of the way out of the chrysalis, exposing the abdomen and wings. The butterfly hangs upside down from the chrysalis or a nearby surface to complete the emergence process. The wings appear folded or crinkled and the butterfly must begin the process of expanding and drying its wings before flight is possible. Meconium is pumped into the venation structures of the wings by wing movement and the help of gravity. Once the wings have fully expanded, the meconium will be pumped back into the body of the butterfly. The small amounts still in the veins of the wings will dry and harden giving the wings a more sturdy structure that will allow flight. It can take anywhere from 30 minutes to 2 hours for a butterfly’s wings to completely dry, this is usually varied according to size. After the wings have dried but before the butterfly will take its first flight it will dispel the excess meconium from its body.