After 17 years underground, a group of cicadas is ready to emerge in several states on the east coast of the United States. Of the genus Magicicada, once these insects emerge from the ground, they are only 4-6 weeks old. In southwestern Virginia are expected 1.5 million cicadas.
"Communities and farms with a large number of cicadas emerging simultaneously can present a significant noise problem"warns the entomologist Eric Day at Virginia Tech."We hope that any nuisance from the ailment is mitigated by how rare – and surprising – this event is."
While some species of cicadas emerge every year, others mature underground for 13 or 17 years. These are known as periodical cicadas and their life cycle is one of the greatest mysteries of nature that we have yet to understand. What we do know is that when the cicadas that live in the soil are mature enough to reproduce and lay eggs, they emerge when the ground becomes warmer, usually starting in May.
These cicadas are considered among the noisiest insects on Earth. According to the scientists, their lament can reach over 90 decibels, the same noise as a lawn mower. These insects pose a threat to tree growers and orchard and vineyard managers, who must plan ahead for swarms to emerge. After mating, the female cicadas lay hundreds of small eggs in twigs and branches, which could cause the withering or division of the branch.
The periodical cicadas they are also beneficial for ecosystems: their appearance naturally turns the soil and prunes the trees, increasing flowers and fruits in the following years. Furthermore, a study recently found the incredible physical properties of the wings of these insects.