Researcher studying cicada emergence in Washington
Our old “friend,” the periodical cicada, as shown in a 2016 file photo.
Researcher Kelly Hougland, a doctoral candidate from Missouri-Columbia, selected Abernathy Field Station in Washington to study whether cicadas use social cues and communication to decide when to emerge from the ground.
Kelly Hougland suspects cicadas get chatty just before surfacing from their 17-year slumber, as they are expected to do soon in this area.
Hougland, 33, a doctoral candidate at University of Missouri-Columbia, chose Abernathy Field Station in partnership with Washington & Jefferson College to study whether cicadas use social cues in addition to soil temperatures to decide when to emerge. Hougland will do various sound and behaviorial tests to see if the insects’ subterranean clicks point to planned, coordinated swarm behavior beyond simple temperature recognition.
The researcher plans to start his research in mid-May – when he suspects the red-eyed bugs will start to appear – and stay through mid-June, once all adults have emerged and bred.
“We had a warm spring, which tells me they’ll appear sooner than the last time, when they emerged on May 30,” Hougland said. “They start to emerge when the soil stays a consistent 65 degrees Fahrenheit, but I’m looking to study if there are other social cues or communication among the cicadas as they emerge … because if it was strictly temperature they were acting on, you’d see a singular, mass emergence. So some may perceive the temperature, or an optimal range, and they ‘tell’ others that aren’t perceiving the variance.”
Another component that leads Hougland to suspect coordinated collaboration is going on is the cicadas burrow tunnels weeks ahead of their actual emergence.
“But we can’t do a field test without disturbing those conditions. So measuring for sounds and correlation with how and where they emerge will be my method,” Hougland said.
Three distinct species comprise the 17-year “brood V” group, but besides subtle marking differences, good luck telling them apart.
“You can hear the differences. Most cicadas have the rise and fall steady drone. Some species (decula, decim and cassini) make a click before the rising drone noise. But the three to four species, with one only appearing in the Midwest, they show how cicadas evolved through different environmental and time factors,” Hougland said.
That droning, which is the males’ mating call, can reach 120 decibels, or the loudness of a jackhammer. That ear-piercing phenomenon is achieved with a specialized organ. Whereas most insects use their legs – picture the cartoon cricket playing its leg violin – cicadas use a tymbal organ in their abdomen, which contain stiff ridges that pop in and out at a rate of several thousand times a second, to achieve a high-pitch frequency. Females don’t have the tymbal organ, Hougland said, because that precious space is reserved for eggs.
Hougland said he’ll also try to track emergence rates of males to females, as males tend to emerge first in anticipation of the females; the females wait it out for males to populate the earth so their chances of survival while mating increase.
“Everything eats them. And their eggs have a 98 percent chance of dying. So mass numbers in the billions is their only defense in nature,” Hougland said.
Another gender quirk in the cicada world is a fungus that disrupts the cicadas’ mating cycle.
“There’s this fungus that attaches and disintegrates the males’ abdomens and actually feminizes them. It makes them react to other males’ mating calls and make attempts to breed with them, thus spreading the (Masspora) fungus,” Hougland said.
That tidbit is enough to gross out anyone, let alone the thought other cultures consume the bugs and celebrate their arrival with elaborate recipes.
“In Columbia, they were making ice cream. Some southern states grill them up … if you catch them right as they’re emerging and white, still soft that’s the best time to eat them – or so I hear. I won’t eat them out of guilt. They’ve just spent 17 years undergound and I’m not going to snatch them up as soon as they get a chance at life. They have enough things eating them.” he said.
The Observer-Reporter plans to follow Hougland and his research during his stay.