BBC Science Focus Magazine
Advertisement
Billions and billions of these cicadas from 15 US states start to come to the surface when the soil above them hits a temperature of 17.7ºC.
Within a matter of weeks, these cicadas will emerge, grow into adults, breed, lay eggs and die, and won’t be seen again for another 17 years.
Advertisement
Counting down the days Colette Lord, 20, an ecology and evolution student at the University of Maryland, measures the soil temperature in a wooded area on campus on 3 May 2021 in College Park, Maryland, USA. The soil measured 14.4 degrees celsius, slightly cooler than necessary for the periodical cicadas from Brood X to emerge. Lord is part of a group of 15 students who are measuring and monitoring the area for the rise of billions of the airborne insects that have been eating and growing under ground for 17 years. Photo by Chip Somodevilla/Getty Images