More than 1 trillion cicadas swarm US East, Midwest

Black, yellow insects have taken over much of US East Coast, Midwest with high-pitched mating ritual.

More than 1 trillion cicadas swarm US East, Midwest

A mass swarm of cicadas have taken over much of the US East Coast and Midwest, emerging after spending 17 years underground.

The Brood X tsunami of the little insects have been spotted as far south as Georgia and as far north as New York. They have also emerged in the Midwest where they have been seen in parts of Illinois and Indiana.

In the US capital region, the bugs have erupted en masse with nary a tree nor shrub free of the black and yellow insets or their shredded shells.

Most of a cicada's life is spent about 1 to 2 feet (30 to 60 cm) below ground where they feast on sap from tree roots. Shortly after they emerge in a form known as nymphs they shed their exoskeletons and grow wings.

It takes a couple of days for their shells to harden, but once they do mating begins and the insects produce a high-pitched and ever-present buzz that can be heard night and day. After mating, females will lay hundreds of eggs in tree branches and shrubs before this brood dies off in late June or early July.

The recently-hatched nymphs will then burrow underground where they will wait 17 years before emerging again.

Some broods run on a 13-year cycle, but Brood X runs on 17-year iterations.

Estimates vary on the number of cicadas in Brood X, but they are widely believed to number in the trillions.