(Posted May 7, 2021)
By Lynn Glispie, Madison County Master Gardener
Brace yourself for a tsunami of cicadas. After a 17-year slumber, they will emerge between May and late June to begin their mating season. In 16 states, Ohio being one, they will prepare for flight, lay eggs, then die after a brief burst of life. Ohio had a “small” burst of them in 2017, but this year we are going to hear billions of them buzzing. If you had them in 2004, it’s very likely you will have them in 2021.
Currently, the cicada larvae are living between one and eight feet underground, not sleeping, but actively tunneling through the earth and dining on the juices of various tree and plant roots. When the soil temperature at a depth of 8 inches reaches approximately 64 degrees Fahrenheit, it signals the cicada larvae that it is warm enough for them to thrive. In April, the cicadas will start making exit tunnels in the soil around trees. These holes are about the size of a dime. Small mounds or turrets on the ground will mark where they will emerge.
After emerging, larval cicadas climb the nearest vertical surfaces and molt, becoming winged adults. The exoskeleton is the shell the cicada sheds when molting and can be found in large quantities on branches and twigs. Cicada shells are valued as an ingredient in Chinese medicine. These medicines are often used as fever reducers and to treat skin conditions and other ailments.
The males sing to attract females. They make the sound by vibrating their abdominal membranes. After mating, the females lay eggs in the tips of trees. The eggs hatch six to 10 weeks later. After hatching, billions of the ant-sized nymphs fall to the ground, enter the soil and feed on the tree juices for another 13 to 17 years, completing the cycle of life. The entire above-ground part of the life cycle happens in a span of two to four weeks.
These large insects are relatively harmless to living things as they do not bite or sting and are not poisonous. They also do very little harm to the plants they feed from. Fortunately, they are not here for long, so enjoy the sounds of spring and happy shell-hunting to all.
Lynn Glispie is a member of the Madison County Master Gardeners. Watch for upcoming details about the program’s new Ask A Master Gardener Help Line, coming soon.