ambience: crickets, Texas integer, hapithus agitator
The chirping of crickets is probably the most recognizable of all insect sounds. Male crickets make the sound by rubbing their wings together, and they take special pains to broadcast the sound over distances, to attract female crickets to mate with. But some of the males never sing at all — and it may just save their lives. I’m Jim Metzner and this is the Pulse of the Planet.
“Now, some species of cricket live in burrows and they shape the entrance to the burrow so that it has the shape of a megaphone or a band shell and directs the sound, and this sound is perceived by females at a considerable distance.”
Gilbert Waldbauer is a professor emeritus of entomology at the University of Illinois. He says that sometimes the chirping cricket loses out in the mating game, to another male cricket that never makes a peep.
“Silent males have the equipment to sing, but they don’t sing. And they lurk near singing males in hope of seducing a female before she gets to the singing male, and sometimes they’re actually successful.”
Now, most of the time, the female cricket will mate with the male that’s actually been chirping. So you might think that, with the odds against their reproducing, the silent male crickets would just die out over time. But they haven’t, and scientists have figured out why.
“It turns out that that may well be an advantage to remain silent, because there is a parasitic fly that homes in on the sound of the male chirping cricket, lays an egg on the cricket, the egg hatches into a parasite that gets into the cricket, and kills it.”
So in some species of crickets, survival seems to depend on having some males that sing, and others that don’t.
Pulse of the Planet is presented by the National Science Foundation. I’m Jim Metzner.