They’re almost here. Actually, the insects are already here.
That’s if you count the immature cicada nymphs lurking just a foot below the ground, as they wait for just the right time to surface and mate. The insects about ready to make an appearance in southwestern Pennsylvania are known the ‘Brood V’ cicadas. And believe it or not, they’ve been hanging out in the ground for 17 years—feeding on tree roots and crawling up and down tunnels they’ve made in the dirt.
But how exactly do cicadas know when is the right time to emerge? Well, Kelly Hougland, a Ph.D. candidate at the University of Missouri has been studying whether cicadas could be using sounds and vibrations as cues to decide when to push up from the ground. He inserted little microphones called accelerometers into a small patch of woodland in Washington County to test this hypothesis.
Thus far, the emergence of cicadas has mostly been predicted by the warming temperature of the soil. But Hougland thinks there may be something social going on too because it’s so critical that the cicadas come out together.
“If a male comes out too late, all the females have been mated with,” Hougland says. “If they come out too early, there aren’t any cicadas around to be eaten instead of them.”
Hougland says cicadas are prime food for raccoons and lots of other animals. Emerging by the tens of thousands in this little research field—and by the billions in the region—ensures that some will go on to create the next generation.
Hougland says most of the cicadas are likely to start popping up within days. And in a week or so, their signature sound will be easier to hear—and hard to ignore.