May 27, 2020
On this episode of the Life in the Carolinas podcast, Carl sits down with John Cooley, an Assistant Professor in Residence at the University of Connecticut. They discuss the emergence of Brood IX in North Carolina, Virginia, and West Virginia this May as well as John’s cicada mapping project and its corresponding app, Cicada Safari, which he is currently promoting.
After a brief introduction to periodical cicadas, John answers some pressing questions regarding the emergence of the 17-year variety. He tells us to think of this type of cicada as a “big boisterous aphid”, as they spend a lot of time sucking on plant juices both as juveniles underground and adults above ground. He says that once you can see mating pairs amid the chorus, “you will know you are really in the thick of the emergence”, and that their time above ground should only last around a month, depending on the weather, before they all die.
Immediately upon emerging, Adult cicadas climb the nearest available tree and shed their nymph exoskeleton. Starting out stark white, they achieve their full, brown coloration within a couple of days. Males feed on surrounding vegetation until they become mature adults, then proceed to sing in order to attract females. John goes into the complicated, three-part courtship that takes place throughout the entire chorus. For the remainder of their respective lifespans, males will continue to look for females and females will continue to lay eggs.
Asked whether cicadas “damage” trees, John replies that “it depends what you mean by ‘damage’”. After all, these species of cicada have been around for millions of years, carrying out their regular activities within the same environment—which include trees—in that time. He hastens to add that “delicate ornamental trees, fruit trees, and saplings” are more prone to defilement simply because they are not a natural part of the Eastern Deciduous Forest.
John says that spraying pesticides will not be enough to take care of the enormous numbers of cicadas in the area; not to mention the damage that will be done to the surrounding environment due to all those chemicals. Instead, John encourages those concerned to invest in anything that physically excludes the cicadas from the branches, such as avian netting, window screening, or cheese cloth. These will probably not exclude every single cicada, but it should exclude enough to prevent the tree from getting damaged.
Apart from periodical cicadas, there are also annual cicadas. While these encompass a number of species, the “loud ones that are often singing at dusk” are known as Dog-day cicadas. John refers to Dog-day cicadas as “the sounds of summer”, as they emerge in July. Speaking of their singing, John mentions that the sound of the swamp cicada can be heard in the original Star Wars film when C3PO and R2D2 land in Tatooine. This is, in fact, a recurring choice in many Hollywood soundtracks because swamp cicadas produce a “scary, rattly sound”.
John grew up in Kansas City and was exposed every year to summer cicadas. He loved hearing them, referring to the yearly experience as “the sound of childhood and summer”. He also had a professor in college who was an expert in periodical cicadas. He piqued John’s interest to the point where he went on to study the Magicicada in his postgraduate education.
Why study something so “esoteric” as periodical cicadas? “In biology,” replies John, “it is the exceptions that are interesting. The exceptions tell us something about how the world works.” On a more practical level, periodical cicadas are a “bioindicator of our forests’ health”. That is, if a good crop of cicadas emerge, “all is as it should be”. The forest is doing exactly what it needs to be doing.