Some luckless cicadas are emerging from 17 years underground intent on mating, only to have their brains hijacked and their genitals replaced by a fungus that infects them just before they surface. The Massospora fungus replaces the lower part of the cicada's body with a "white plug of fungus" and produces a natural amphetamine called cathinone that makes the insect "hypersexual," with prolonged stamina, Matt Kasson, an associate professor of forest pathology at West Virginia University, tells NPR. Infected male insects continue to attempt to mate with females but also imitate females to attract—and infect—as many cicadas as possible. During the mating attempt, neither partner appears to notice that there is fungus where the infected cicada's genitals should be. "It's a failed mating attempt, of course, because there's no genitalia back there," says Kasson.
Brian Lovett, another West Virginia University researcher, tells the Washington Post that the abnormal behavior makes observers realize, "This is a zombie ... something strange is happening here." In the later stages of infection, the cicadas shed spores, which inspired the nickname "flying salt shakers of death," Lovett says. Researchers—who hope to learn more about Massospora as Brood X emerges this year—believe the fungus infects only a small proportion of cicadas, probably fewer than 5%. Kasson notes that with yearly cicadas, as opposed to periodical ones, the fungus uses the psychedelic compound psilocybin to turn them hypersexual. He says infection doesn't appear to cause any pain. "Everybody's having a good time while they're infected," he says. "So I don't imagine there's much pain—maybe a desire to listen to the Grateful Dead or something like that, but no pain." (Read more cicadas stories.)