Females in Charge
Insects in Brazil go beyond simple behavioral sex-role reversal. In these animals, the females use an erectile organ to penetrate the male’s genital chamber.
Like most sex-role reversed organisms, populations of insects called Neotrogla have aggressive, promiscuous females and males who tend to be choosier about whom they mate with. But unlike other species that follow such a reversed pattern of sex-specific behaviors, these tiny winged insects seemed to have also swapped genitalia.
In a study published last week (April 17) in Current Biology, researchers described the female Neotrogla’s “elaborate penis-like organ,” which they call the “gynosome.” The organ is used “as an intromittent organ [that] anchors the female to the male [during copulation],” the researchers wrote, which can sometimes last for days and often results in the transfer of “a large and potentially nutritious ejaculate” from the male. The authors thus speculate that the “genital evolution in Neotrogla is probably driven by reversed sexual selection with females competing for seminal gifts. Nothing similar is known among sex-role reversed animals.”
http://www.the-scientist.com//?articles.view/articleNo/39752/title/Females-in-Charge/