Swarmageddon: US prepares for invasion of plague of cicadas

Billions of cicadas are set to emerge from 17 years underground (Reuters)

The US East Coast is preparing for a once-in-a-generation infestation of flying insects as billions of cicadas emerge from 17 years underground for a short-lived breeding frenzy known as “Swarmageddon”.

Although the insects pose no threat to people or to crops, their emergence will be marked by a mating chorus as loud as a pneumatic drill as the insects complete their unusual life cycle.

Many Americans living in the heavily-populated belt from Washington, through New York, to Boston, are planning to leave rural areas to seek refuge from the plague of cicadas in cities and by the sea, while television networks are suggesting people equip themselves with noise-proof headphones.

The cicadas, which have already begun emerging in southern states, will appear along the East Coast at some point over the next few weeks - whenever the temperature eight feet underground hits a stable 18C.

Juvenile cicadas, or nymphs, live underground for most of their lives, growing from their larval stage into bugs with strong tunnelling legs. When it is time to emerge, they use their legs to climb backwards out of the ground before climbing a tree to shed their skins - creating a crunchy layer on the ground. There are likely to be around 1.5 million cicada for every acre of infested land.

They then spread their wings and set of to find a mate. Males use tymbals - noise-emitting organs in the abdomens - to signal to prospective partners, while females add to they cacophony by snapping their wings in response. 

After mating, females will lay eggs in trees, which hatch later in the year, with the young cicadas falling to the ground, before burrowing under, not to be seen for another 17 years. The adults themselves die off after around four to eight weeks.

Some cicada species have an annual life-cycle, but the chance to see the 17-year cycle species - magicicada - is a big opportunity for insect scientists. 

"The periodical cicadas are friendly insects and fun to watch," entomologist John Cooley, of the University of Connecticut told The Daily Telegraph. "The people who say that it's gross are probably the same people who are quite happy to catch the subway in Manhattan in close proximity to a million-plus cockroaches. Give me cicadas any day."