Some broods emerge in 13-year cycles and others in 17-year periods and while there is no definitive explanation for this phenomenon, many entomologists believe the cicadas have developed this as a defensive move against predators. The task is to then ascend a tree, with the males creating what Raupp calls a “big boy band” of noise to attract females for mating. At first, the nymphs are a ghostly white before shedding their skins and developing a hardened exoskeleton. Raupp scrabbled in the dirt to show the small holes where more fortunate cicadas managed to tunnel to daylight using their shovel-like front legs. Their foot-deep refuges became tombs, even before the cicadas could run the gauntlet of the overland. In the past 17 years, much of the ground containing cicadas has been paved over for roads and driveways and shopping malls. Millions, perhaps billions, of the insects don’t even make it to this point. The amber-colored exoskeletons shed by the cicadas litter the seething ground and pockmark the trunk and branches of the elm tree. Cicadas flail around in a stupor on their backs, some lie squashed, others are picked off by a red-shouldered hawk that is shoveling insects into the gaping maws of two ravenous chicks in a nearby nest. The scene is not only raucous – a swarm of cicadas can produce a sound that reaches around 100 decibels, louder than a revving motorcycle – but also grisly. Photograph: Gabriella Demczuk/The Guardian Cicadas swarm the trees of a home in Columbia, Maryland, on 21 May.
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