PLANET EARTH Seasonal Forests

By June the days are at their longest and all across the northern hemisphere, the broad leaves are hard at work. On the east coast of North America it seems like any other summer's evening, but tonight is special. After seventeen years underground creatures are stirring. The nymphs（仙女） of the periodical cicada have been biding their time. Now they march like zombies towards the nearest tree, and start to climb. At first, there are merely thousands but soon, more than a billion swarm all over the seasonal forest.



The biggest insect emergence on the planet is underway. They invade the upper branches, where they climb out of their external skeletons and assume their adult winged form. At first they're white and soft, but they have until dawn to complete their transformation. After an absence of seventeen years, the seasonal forest is now overrun by cicadas. The adults are clumsy and very edible. For turtles and other inhabitants of the seasonal forest this is a feast they're lucky to see once in their lifetime and they gorge themselves while they can.



Times have never been so good. The cicadas have no defenses and virtually offer themselves to their attackers. The stream of insects is so relentless that soon all the predators are full to the point of bursting and still the cicadas come. With the predators overwhelmed the survivors can achieve their purpose. After mating, the adults lay their eggs and then their job is done. In just a few days they will all die and the seasonal forest will fall silent.