When a male cockroach wants to mate with a female cockroach very much, he will scoot his butt toward her, open his wings and offer her a homemade meal — sugars and fats squished out of his tergal gland. As the lovely lady nibbles, the male locks onto her with one penis while another penis delivers a sperm package.
If everything goes smoothly, a roach’s romp can last around 90 minutes. But increasingly, cockroach coitus is going really, weirdly wrong, and is contributing to roach populations in some places that are more difficult to vanquish with conventional pesticides.
Back in 1993, scientists working at North Carolina State University discovered a trait in the German cockroach, a species that inhabits every continent except Antarctica. Specifically, these new cockroaches seemed to have no affection for a form of sugar called glucose, which was strange because — as anyone who has ever battled against a cockroach infestation knows — cockroaches normally cannot get enough of the sweet stuff.
So, where did these new, health-conscious cockroaches come from?
It seems we created them by accident, after decades of trying to kill their ancestors with sweet powders and liquids laced with poison. The cockroaches that craved sweets ate the poison and died, while cockroaches less keen on glucose avoided the death traps and survived long enough to breed, thus passing that trait down to the next cockroach generation.
But, wait, there’s more! We’ve not only introduced physiological changes; behavioral changes have expanded the need for re-examining the sex lives of these critters.