Q: What are cicadas?
A: Cicadas are oval-shaped insects, from 3/4 inches to 2 inches long, that produce a buzzing or clicking sound by flexing a pair of drumlike structures called tymbals, similar to a plastic bottle popping back into shape after being compressed.
Q: When is cicada season?
A: Periodical cicadas are heard in May and June, while annual cicadas are heard from late June through August. Cicadas will live in the soil as nymphs from two to 17 years, depending on the species. Once they emerge from the soil and change into an adult, they will only live five or six weeks.
Q: Why do some cicadas only emerge every 13 or 17 years, compared with others that emerge annually?
A: The 13- and 17-year cicadas are known as periodical cicadas, meaning there is a period of time between occurrences. The nymphs spend 12 or 16 years, respectively, in the ground before they emerge and change to adults.
There are two broods of each of the 13- and 17-year cicadas found in Missouri, and each brood emerges on their own cycle. The last time two or more broods emerged the same year was 1998.
The periodical cicadas start emerging in May and live through June. Though annual cicadas actually spend two to five years in the ground, there is at least one generation that emerges each year in late June or early July.
Q: How loud is a cicada's buzzing?
A: Cicadas can get as loud as 90 to 100 decibels; that is as loud as a lawn mower, dirt bike or tractor. People who live in the city are far less likely to get the full effect of the cicadas' sounds, since cicadas prefer trees, shrubs and soil.
Their “music” is more of a nuisance to rural or suburban landowners than a hearing hazard. If the noise is bothersome, wear hearing protection such as earplugs or earmuffs.
Q: Which cicadas can people expect in Missouri?
A: Periodical cicadas, when they do appear, are between 3/4 and 1.5 inches long with a black body with orange markings and red eyes. The annual cicadas, also known as “dog day cicadas,” are present every year from late June through August (the dog days of summer), and are around 2 inches long with a brown, green and white body with dark-colored eyes.
For the next few years, we should expect to only hear the annual cicadas; it won’t be till 2024 when our next 13-year cicadas will emerge and 2032 before we hear the 17-year cicadas.
Tim Smith is the administrative assistant at the Shoal Creek Conservation Education Center in Joplin.