The emergence of Brood 9 of the 17-year periodical cicada this spring in northern Wilkes and parts of Surry, Alleghany and Ashe counties added an appropriately odd backdrop to the year of the COVID-19 pandemic.
Stories of experiences with these unique insects in May and June will likely be repeated for years to come. My clearest memory of the last day in the eighth grade at Wilkesboro Elementary is carrying out a plan to gather shirttails full of cicadas at the school bus stop and releasing them on the school bus.
Earlier this month, sound systems of some Wilkes churches with parking lot worship services due to the pandemic had to be turned up due to the droning song of millions of male cicadas trying to attract females.
People mowing their lawns in Mountain View were startled when cicadas landed on them, apparently attracted by the sound of the mowers.
Fishermen discovered the effectiveness of live cicadas as bait, used without sinkers so the insects floated while flapping their wings. They worked well for bass, catfish and bream.
In other parts of the world, people eat cicadas. According to www.cicadamania.com, the insects are barbecued, boiled, broiled, baked or sauted. Around here, most people might prefer them fried. To save time and trouble, they can also just be eaten raw.
Brood 9 of periodical cicadas last emerged in Wilkes and other area counties 17 years ago in 2003. Ironically, 2003 was the year of another coronavirus pandemic: SARS (Severe Acute Respiratory Syndrome). SARS was more deadly than COVID-19 but harder to transmit from person to person. The impact of lessons from SARS during the COVID-19 pandemic appear to be lacking.
Going back 17 years and then 17 more years, the United States experienced severe influenza B epidemics in 1985-86 and 1968-69 respectively. Another viral epidemic, polio, peaked 17 years before 1969 in 1952.
This isn’t to say scientists believe there is a connection between communicable diseases and cicadas. For one thing, a particular brood of 13- or 17-year cicadas emerges in only one region of the country.
Nevertheless, one can’t help but wonder what epidemic or pandemic might be occurring when Brood 9 next emerges in these parts in 2037.
It’s remarkable that multiple broods of 13-year and 17-year periodical cicadas each stick to their respective schedules of emerging every 13 or 17 years in different parts of the U.S.
Scientists believe these brood cycles developed as a way to survive predators, since predators can’t seriously threaten the species when so many cicadas emerge at one time.
How they follow these 13- and 17-year cycles is one of the great mysteries of the insect world. The dominant theory is that these emergence schedules are based on environmental cues that signify the passage of years, especially composition of xylem fluid in tree roots they feed on changing when trees leaf out.
Just why some emerge on 13-year cycles and others every 17 years is another matter.
The particular day a brood emerges is believed to be triggered by accumulated ground temperature.
“Nature” magazine reported that in 2007, one brood of cicadas emerged a year early after unusual weather caused trees to grow and drop leaves and then grow leaves again in a single winter. This appeared to affirm that cicadas count the years based on tree leafing cycles.
The impact of our increasingly aberrant weather on this natural timetable is left to be seen.