You think you know them – but the 17-year cicadas you recognize as flying creatures that make loud buzzing sounds in early summer have entire secret lives underground.
Pretty soon now, you should be seeing those black insects with red eyes and membranous wings flying about.
They are Brood IX of one of the three Magicicada species which are expected to hatch between now and early June.
As the flying cicadas we can see and hear, they will live between four to six weeks, then die. That adult stage, however, comes at the end of having lived 17 years underground.
The periodical, including 17-year, cicadas, “are members of the large insects order Hemiptera, which also includes aphids, scale insects, leafhoppers, treehoppers, planthoppers, spittlebugs, and true bugs, such as the familiar stink bugs and their allies,” said Dr. Kal Ivanov, associate curator of invertebrate zoology at the Virginia Museum of Natural History.
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Some people mistakenly call them locusts, he added, but locusts are grasshoppers, which belong to a different order.
Annual cicadas (which actually live for a few years underground – but not a set number of years like the periodical cicadas) are green and a bit bigger than periodical cicadas.
The 17-year cicadas are about an inch long. The adults are black on top and reddish-black on the bottom, with big red eyes and two pairs of clear, membranous wings with reddish veins, Ivanov said.
Instead of jaws for chewing, they “have modified mouthparts, which form a piercing-sucking stylet used to feed on liquids,” he said.
Their lives begin when nymphs hatch from eggs laid into grooves in bark and fall to the ground. Those nymphs burrow into the soil and find their way to tree roots, where they will live, sucking juices from roots for sustenance.
“Cicada nymphs remain underground where they feed on the juices of plant roots and transition through five instars (stages) as they grow and increase in size. While underground, the nymphs move deeper below ground, feeding on larger roots,” Ivanov said.
After 17 years living underground, on a day where the soil eight inches down reaches 64 degrees – and often prompted by a nice, warm spring rain – that group, called brood, of cicadas emerge from the ground.
Scientists haven’t figured out what triggers this amazing, exact timing.
“The year of cicada emergence is likely determined by an internal molecular clock, although the exact mechanism is not yet completely understood,” Ivanov said.
Some factors that help that internal clock along would include “yearly tree leaf out and changes in the composition of the plant juices on which they feed,” he said.
By the time they emerge, they are at the fifth instar stage. They climb onto suitable plants or trees nearby and molt for the last time, turning into their final and adult stage, which will last barely more than a month before they die.
“That short lifespan has only one purpose – reproduction,” he said.
The males get together in clusters in what are called “chorus” trees, Ivanov said. Males have specialized accordion-like body parts on the sides of their abdomens, called tymbals, which they use to make noise.
That noise attracts the females. After mating, “the female cuts V-shaped slits into the bark of small twigs with her saw-toothed ovipositor and lays eggs. The eggs hatch in six to 10 weeks,” he said.
Then the whole process begins anew.
Organizers of the website Cicada Mania track cicadas, and because of pandemic-related travel restrictions, are asking the public to help track them since researchers can’t move about as freely. Cicada sightings can be reported on the app Cicada Safari App.
Cicada Mania lists areas in Virginia where they are expected to emerge: Blacksburg, Bland, Callands, Christiansburg, Covington, Dry Pond, Ferrum, Martinsville, Roanoke, Salem, Vinton, and more, and the counties of Allegheny, Bland, Franklin, Henry, Montgomery, Patrick, Pittsylvania and Roanoke.
The website Magicada.org has a map showing the locations of various broods of cicadas. “Brood IX is of interest, because even though our existing maps of it are fragmentary, it appears to exemplify the puzzle-piece nature of periodical cicada broods.,” the website states.
Holly Kozelsky is a writer for the Martinsville Bulletin; contact her at 276-638-8801 ext. 243.