By Susan Milius
After more than a decade of searching, an international team of scientists has found the main gene that separates the girls from the boys among honeybees.
Called csd, it’s the first sex-determining switch sequenced in an animal in which females typically grow from fertilized eggs and males from unfertilized eggs, according to Robert Page Jr. of the University of California, Davis. Called haplodiploidy, this arrangement governs sex determination in some 20 percent of animals, including ants, bees, thrips, white flies, ticks, and mites.