April 19, 2021 - Podcast

Episode 118—Cicadas, and SARS variants

For many people, there is nothing creepier than billions of insects emerging from underground to wreak havoc on trees across 15 states. But that is exactly what will happen next month when Brood X, a group of periodical cicadas, tunnel out of their 17-year sleep and take over yards, fields and woods. Keith Clay, a distinguished professor emeritus in the Indiana University Bloomington biology department, says areas like southern Indiana, Illinois, Kentucky, Ohio, Tennessee and other eastern states will see the highest number of cicadas due to their trees, which are what cicadas need for sustenance throughout their short lives. Trees are essential for periodical cicadas since they feed on the xylem (plant vascular tissue) from tree roots, Clay says. Unlike locusts and other insects, they will not eat foliage or other vegetation when they emerge. Also, because there are so many of them, the Brood X cicadas do nothing to defend themselves against predators — birds, squirrels, raccoons, fish, lizards, snakes and sometimes people. IU biologist Armin Moczek says trees will face damage when the females lay their eggs in slits that they cut into the terminal ends of tree branches. Those grooves often kill small branches on the trees. Those end branches are the location where the fruit of oaks and other nut-producing trees grow. With those branches damaged or killed, there will be many fewer acorns and other nuts this fall for squirrels and other wildlife.

In other news, as more people become vaccinated against COVID-19, some people are worrying about new variations -- or variants -- of the virus that are becoming more common and rapidly spreading throughout the world. Ryan Relich, associate professor of clinical pathology and laboratory medicine at IU School of Medicine, says variants -- a virus that is genetically different from the version of the virus that was first characterized by scientists -- arise all the time, and it's not surprising that a large variety of SARS-CoV-2 variants have emerged. Fortunately, many of those variants don't stick around, but the ones that do are of interest and, potentially, of concern. Relich says scientists and public health officials need to know if variants that do stick around could spread more easily, could cause more severe disease, or are likely to evade the protection offered by vaccines. Relich says the main reason we should pay attention to variants of SARS-CoV-2, and of any virus for that matter, is because they have unknown potential. We may find variants that cause more severe disease or are more contagious than the original, he says. On the other hand, some variants may be less dangerous than the original virus, which is why researchers need to study them. Relich says everyone should prioritize getting the COVID-19 vaccine as soon as possible to help protect you and those around you not only from the original SARS-CoV-2 virus but from the known variants as well. In addition, he says, everyone should remain vigilant about the same health and safety precautions we've been practicing for over a year now including wearing a mask, physically distancing, washing our hands frequently and avoiding large crowds or gatherings.