Parnassius Clodius, Mated Female

Day 281: All right, class, settle down. Today, we will be venturing into the somewhat embarrassing subject of how to tell girls from boys, i.e., "the birds and the bees" as it relates to the peculiar anatomy of the Clodius Parnassian butterfly (Parnassius clodius). Our specimen here is not perched on a nodding flower. The hollow, keel-like white structure you see beneath the black body is called the "sphragis," and originates as a gelatinous secretion deposited by the male during mating. This secretion hardens into a plug which prevents sperm from escaping the female's body, giving much better odds for reproductive success. Parnassians are one of the few families of butterfly which exhibit this unusual anatomical characteristic.