HAMPTON ROADS, Va. (AP) — Ants. Mosquitoes. Chiggers. Was this summer buggier than normal or did it just seem that way?
“I don’t think it’s been any worse this year — I mean, summer’s always bad for bugs, right?” said Bob Borlase of Hampton Roads Termite & Pest Control. “Maybe it just seems worse because we’re living with them more.”
In other words, the pandemic has us spending more hours in our homes, yards and outdoors in general, where we simply notice the bugs more.
At Virginia Tech’s entomology department, James Mason said the variables are too numerous for researchers to do a broad insect count for any given year. Too many species and factors — like “location, time of day, which day, recent rain” and more, he said.
But in Tech’s neck of the woods, there’s one bug researchers have definitely seen more of this year: Periodical cicadas, programmed to emerge every 13 or 17 years, depending on the geographic group — or brood.
Periodic cicadas like this one emerge every 13 or 17 years. The summer of 2020 was go-time for Brood IX, which filled parts of Virginia, North Carolina and West Virginia with 1.5 million insects per acre.
The summer of 2020 rang the alarm clock for a 17-year batch labeled Brood IX, whose home straddles three states: West Virginia and the western parts of Virginia and North Carolina.
Unlike those cicadas, the ones that inhabit Hampton Roads are annual varieties, commonly called dog-day cicadas. Usually greener or browner than the mostly black-hued, red-eyed periodicals, dog-day cicadas emerge every summer. Their mating call — a loud, persistent droning buzz — is baked into the soundtrack of the hottest months of the year.
Like their periodical relatives, they spend winter underground in the form of nymphs attached to tree roots, surviving on sap. When the soil warms, they dig their way out, climb trunks and molt, shedding their beetle-like outer skins in favor of a winged phase.
Hampton Roads is home to only annual cicadas like this one, photographed shortly after molting into its winged phase. As it hardens, its colors will darken.
The males are the noisy ones, serenading females by vibrating a drum-like membrane in their abdomens. In concert, their love song can be almost deafening. Some larger species can top 100 decibels, the equivalent of a chain saw and approaching painful to the human ear. Smaller species can produce a pitch so high it makes dogs howl.
Females cut tiny slits in bark to implant their eggs. Larvae fall to the ground, burrow as deep as 8 feet in search of roots and the cycle continues.
Cicadas live across the globe — 3,000-plus species, ranging 1-2 inches long — but periodicals are found only in North America. Early European colonists, having never seen such a thing, mistook them for locusts, invading from nowhere like some age-old Biblical plague.
But cicadas don’t devastate crops or even damage trees much. At least the annual ones don’t.
“The periodicals prefer smaller, younger tree branches, which get broken easier,” said Mason, the spokesperson for Tech’s entomology department, who has his own degree in the same field.
Plus, “periodicals emerge in much larger numbers than annuals,” he added.
The scale of Brood IX’s reappearance this spring was estimated at 1.5 million insects per acre. That’s enough to put a hurting on orchards, vineyards and the like, not to mention create a substantial racket. Mason compared their cacophony to a “field of out-of-tune car radios.”
At least it’s temporary, he said, and made more tolerable by the flat-out wonder of the phenomenon.
No one knows how periodicals emerge in unison after all those years underground.
Or why they tarried so long in the first place.
Theories abound. Maybe the nymphs can tell time by monitoring chemical aging inside their own bodies. Or they can detect the passage of years by the seasonal rise and fall of sap in the roots they’re feeding from.
Their long waits in the dark might help break a link with predators. By appearing only at odd intervals, they avoid synched-up surges in predator populations.
Their clamor — the loudest in the insect world — could also be a foil for predators. Researchers speculate that the volume is troublesome for birds, interfering with their communication, making it harder for them to descend on a brood in flocks.
But why are there no periodicals in Tidewater?
Could be development. Periodicals favor deeply forested regions.
Also, they don’t spread well. While their yearslong subterranean stage gives them the longest lifespan of any insect, their days in the sun are brief. Adults don’t eat, dying shortly after they’ve laid the next generation.
“They have to stay close together so they can find each other quickly,” Mason said.
Adults of the annual sort enjoy life a bit longer. Mason said that’s because they do eat, siphoning fluids from plants through a straw-like apparatus until cold weather does them in.
Ours will surface again in the spring. Holes will appear in the soil near trees, about the diameter of a finger and encircled by a mud “turret.” Cast-off husks will be left clinging to trunks. And an icon of summer’s ballad will be back.
On the other hand, members of Brood IX won’t be seen again until 2037.
But don’t expect quiet in periodical land.
Mason says Brood X — the biggest in the U.S., sprawling across most of the eastern side of the country — is due above ground in 2021.