Scientists in Argentina discovered that male fruit flies inject females with a substance that makes them sleepy during mating. The research was published in the journal PLOS Genetics.
Researchers at the Bariloche Atomic Center and Leloir Institute raised a group of fruit flies in the lab and watched them with webcams for four days.
Scientists have discovered that “virgins” are the only females who wake up in the morning right after turning on the lights. They suspected that the cause of the flies’ sleepiness was a peptide that the males injected into them during mating. This has been previously shown in other studies to change the female’s scent and make her less attractive to other males.
The biologists repeated the experiment and first turned off the peptide-sensitive brain cells in a few females. As a result, such flies began to wake up simultaneously with the “virgins”. The scientists hypothesized that the peptide not only changes the female’s scent, but also interacts with the parts of the brain responsible for sleep.
This male behavior is likely an evolutionary tactic to help males reproduce and prevent females from mating with other males.