This is the third and my last post on butterflies per reading the book. "A World for Butterflies: their lives, behavior and future" by Phil Schappert, a Lepidopterist (i.e. butterfly biologist) at University of Texas. As the author pointed out the purpose of butterflies' life is to reproduce, butterflies are "flying sex organs". Butterflies' courtship is very interesting.
Preparation for courtship
To mate with a female butterfly, a male butterfly has to provide a nuptial gift during copulation, in the form 'spermatophore', which contains nutrients, salts and sperms. The spermatophore can weight as much as half the males body weight!! A female butterfly can actually assess the ability of a male butterfly to provide a large nuptial gift based on their odor. So before seeking out mates, a male butterfly has to work hard to to collect salts, nutrients - some specific compounds.
Before starting courtship with females, a male butterfly may either stake out on a tree or other places, perching there, waiting for female butterflies to come; or they may patrolling certain areas to look for mate. When males are perching, they will always meet females in flight; when males are patrolling, they may see females flying or resting. Butterflies courtship depends on pheromones, a species "signature scent" or odor and a series of signals and responses - sounds familiar? When males meet females when females are resting on ground or vegetation, males will hover over the female, fluttering, touching her by his wings, legs or antennae. If the female accept the advance, she will flutter her wing slowly; if she rejects the advance, she will keep her wings open or close and hold them steady. When males meet females during flight, the male will attempt to fly under her then up in front of her in order to pass their pheromones to the females antennae by their forward motion. Females reject the courtship by continuing flying, they accept the courtship by alight on ground or vegetation's. Once the female accept the male advance, then the male will land beside her, flicking wings, touching antennae, or posturing while facing each other. Eventually they will face the same direction, the male will curl his abdomen around to try to grasp hers. A willing female will extend and offer her body for coupling. Even at this stage, things can go wrong, a female may hold her abdomen up between her partially close wings to decline copulation. Female butterflies in many species mate once in their life time; male butterflies typically mate many time. This leads to the shortage of female butterflies. In some species of butterflies, male butterflies actually mate with female in chrysalis right before or after the female butterfly eclose, without any courtship.
Butterflies sex organ is at the end of their abdomen. Females have a pair of ovaries that contain ovaioles which develop individual eggs. Males have a pair of valve, or collapsers for grabbing or holding on to female during intercourse. During copulation, the male butterfly insert its adeague, or penis into the duct in females that leading to the eggs, depositing the nuptial gift of spermaphore. Female will need it later for laying eggs When they copulate, they will eventually in a back-to-back position. I observed butterflies joined together a few times before, and found its interesting, not knowing they were actually having sex then. The author and other lepidopteris made many observations of butterflies sexual behavior - including mate-carrying, one carries the other flying while mating; fighting for mate; competition for mate (caught on camera) - two male butterflies tried to pull the female away from her mating partner while they were still joined! Male to male interaction - homosexual behavior in butterflies?! Triangle relationship .... Like dramas played out in human.
Note: Pictures of the mating butterflies were downloaded from http://www.aworldforbutterflies.com/