On 10 May, I had my first sighting of this year’s periodical cicada in Northern Virginia. For seventeen years, three species of Magicicada, the periodical cicada (M. septendecim, M. cassinii, M. septendecula) have been living about 61 cm (2 feet) underground beneath trees across portions of eastern North America. In May 2021, individuals in Brood X (sometimes known as the Great Eastern Brood) began to emerge in the trillions from their long sojourn when soil temperature reached a consistent temperature of 18 degrees C (64 degrees F) or higher.
The last time Brood X emerged was in 2004. For those who witnessed that appearance, or previous ones, Brood X at times feels like a science fiction movie with the creatures swarming and the loud (up to 90 decibel) mating song of the males drowning out conversations (I wonder how the rest of the world will react to our Zoom call being joined by singing cicadas!).
Magicicada are mostly harmless, neither biting nor stinging. Members of the order Hemiptera, the nymphs spend their underground life harmlessly consuming xylem fluids from the roots of deciduous forest trees; the adult female, which deposits its eggs in small slits cut into the ends of branches, rarely causes damage to mature trees and there is speculation that the cicada pruning leads to more abundant leafing and fruiting the following year.