Horror scenario for insect haters: double cicada invasion is imminent

Billions upon billions of insects will populate parts of the United States. Some experts even expect there will be at least a trillion of the loudly chirping cicadas by June. A horror scenario for insect haters, even if the animals are harmless.

The cicadas, recognizable by their red eyes, have been waiting a long time to be used: their nymphs – comparable to the larvae of other insects – burrowed in many years ago. In spring they climb out of the ground at night as soon as the earth’s temperature has warmed to around 18 degrees.

• From the archive: “Don’t call 911”: Loud cicadas unsettle US citizens

After hatching, the nymphs molt, shed their exoskeletons – black chitinous shells – and populate the trees. The male insects of the genus Magicicada then begin to attract a female partner for reproduction with a deafening chirp.

“Up to 110 decibels loud”

“In areas of high concentration, when all the males chirp at the same time, it can be up to 110 decibels, which is close to the noise level of an airplane turbine,” said entomologist Floyd Shockley of the Smithsonian Museum of Natural History in Washington. “When I’m in an area with a high concentration of cicadas, I often use earplugs because that’s close to a level where hearing damage occurs.” Experts compare the chirping of a single male cicada to the noise of a lawnmower or motorcycle.

Important year

This year is particularly significant because there will be two huge swarms around the same time, says the entomologist. This combination, including probably a small geographical overlap between the swarms, last existed 221 years ago, i.e. in 1803. “No one alive today will experience this again,” he emphasizes. The largest swarm of cyclically occurring cicadas, the so-called brood XIX (Roman 19), slumbered underground for 13 years, brood XIII (13) for even 17 years. At that time, George W. Bush was still president in the USA, and 2007 was also the year in which the first iPhone came onto the market. Scientists cannot say for sure why the cicadas adhere to certain cycles of appearance.

Expert Shockley assumes that over a trillion cicadas are likely to hatch in the 17 affected US states from April to June, i.e. more than 1,000 billion. “It will definitely be more than a trillion, maybe several trillion.” Researchers at the University of Connecticut are also predicting several trillion cicadas this year. The insects will settle primarily in forest areas, rather than on agricultural land or in urban green spaces. If you assume there are around a trillion cicadas and chain the insects, each two to three centimeters long, together, the result would be an almost endless chain. “It would reach to the moon and back several times,” Shockley estimates.

“It’s good for the trees”

The last major wave of cicadas occurred in 2021, when brood X hatched. This year, the first large swarms will probably appear towards the end of April in southern US states, such as Mississippi, Alabama and Georgia, as soon as the ground has warmed sufficiently due to spring-like temperatures. In May, Brood XIX, known as the Great Southern Brood, is expected to spread north and towards the east coast. Things should really get going in Illinois in the north of the USA by June at the latest: Brood XIX will spread in the southern part of the state, while swarms of the smaller Brood

According to experts, there could be more than a million cicadas in the area of ​​about half a football field in some areas. “In parts of Chicago, the last time Brood XIII hatched, they had to use shovels to clear streets and sidewalks of dead cicadas,” Shockley said.

However, cicadas, which feed primarily on plant juices, are not comparable to a biblical plague of locusts: during their short life of up to six weeks after hatching, they do not plunder fields or devastate landscapes or gardens. On the contrary, if the adult cicadas die en masse, their lifeless bodies will fertilize the soil. “It’s good for the trees,” emphasizes Shockley.

Cicadas can hardly defend themselves and are not good flyers; sometimes they simply fall to the ground – which provides plenty of food for birds, squirrels and other animals. Many are eaten, but their survival strategy is based on appearing in large numbers. If the males are successful in their loud advertising and the females are fertilized, the latter slit open young tree branches and lay their eggs there. The adult cicadas die soon after their first and last act of reproduction. After several weeks, the nymphs hatch and then bury themselves in the ground for years. There they live on a nutrient-rich liquid that they suck from tree roots. The next generations of Brood XIX and Brood XIII will hatch in 2037 and 2041, respectively.