Climate change affects the emergence in two main ways, Kritsky said. The first is a trend toward earlier emergence driven by warmer spring weather. In southwest Ohio, one area where Kritsky has studied historic data, mass cicada emergence occurs an average of two weeks earlier than they did prior to 1950.

Why do Brood X emerge?

A combination of suitable soil temperature and weather has prompted billions of cicadas, known as Brood X, to begin swarming large parts of the eastern United States. The insects last emerged in 2004, and although their loud mating calls can be distracting, they are not directly harmful to people.

What is the point of Brood X cicada?

Cicadas are mostly beneficial. They prune mature trees, aerate the soil, and once they die, their bodies serve as an important source of nitrogen for growing trees.