US to get buggy as 2 cicada groups emerge together

CICADAS, the noisy but rather tame insects that spend most of their lives underground, are poised to put on quite a show starting this month in a wide swath of the US.

Two sizable adjacent broods of periodical cicadas – the kind that spend a specific number of years underground as nymphs before popping up together for a brief bacchanalia of singing and mating – are set to emerge simultaneously, one concentrated in Midwestern states and the other in the South and Midwest.

These two broods – one on a 17-year cycle and the other on a 13-year cycle – together span parts of 17 states. And, according to experts, they will number more than a trillion.

“They live as adults for just a few short weeks and then die after reproducing. In total, the adult portion of their extremely long lives is less than 0.5% of their total life – 99.5% of their life is spent underground,” George Washington University entomologist John Lill said.

These two broods emerge together only once every 221 years, last occurring in 1803. While nymphs in small numbers are already being seen, the first big wave in the coming weeks is expected in the southernmost areas of the broods in Louisiana, Mississippi, Alabama and Georgia, with the cicadas further north emerging in subsequent weeks. The last cicadas in these broods will be lucky to see July.

“This is the first time these two broods are going to be emerging in the same year since Thomas Jefferson was in the White House,” said entomologist Floyd Shockley of the Smithsonian’s National Museum of Natural History. Cicadas are relatively large insects – 2.5-5cm long – with sturdy bodies, bulging compound eyes and membranous wings.

The 17-year cycle Brood XIII is found in northern Illinois, eastern Iowa, southern Wisconsin and a few counties in north-western Indiana.

The 13-year cycle Brood XIX is distributed in Alabama, Arkansas, Georgia, Indiana, Illinois, Kentucky, Louisiana, Maryland, Missouri, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee and Virginia.

There are more than 3 000 species of cicadas globally. Only nine are periodical, and seven of those are found in North America.