Some insects, like crickets, chirp. Some insects, like bees, buzz. And some insects, like the famous cicada, really buzz. But what else do you know about the cicada besides its infamous noise? Keep reading to learn a little bit more about this interesting insect.
What exactly are cicadas?
Cicadas are insects, grouped into the family Cicadidae for their sound-producing abilities and certain shared characteristics. Cicadas belong to the Homoptera order, along with leafhoppers, aphids, and whiteflies. Though one species of cicadas are sometimes referred to as the 17-year locust (more in the types section below), this is a misnomer as cicadas are not, in fact, locusts.
What do cicadas look like?
When it comes to identifying cicadas, there are a few key physical characteristics:
- Adult cicadas are roughly 1 inch to 1 ½ inches in length, though this can vary based on the species
- Both nymph and adult cicadas are very stout-bodied
- Cicadas usually have dark brown and green bodies
- Adult cicadas have two pairs of clear wings, with the first pair being much longer than the abdomen
Cicada nymphs are smaller and do not have wings like adult cicadas. This may cause some people to think they resemble beetles. In fact, according to the University of Minnesota Extension, nymph cicadas have been described as “beetles that turn into flies.” When nymph cicadas first shed their skin to become adults, they have much lighter bodies that wil l eventually darken and harden.
What about that buzz cicadas make?
When it comes to identifying cicadas, knowing about the sound they make is as important—if not more—than knowing about their common physical characteristics. Below are some interesting details about that infamous buzz:
- While cicadas are perhaps most well-known for their humming or buzzing, each species of cicada has specific mating calls, ranging from clicking to loud buzzing. This buzzing noise has been compared to that of a power-line hum.
- Only males produce noise. It is their mating call to female cicadas.
- A cicada’s thorax is similar to violins or guitars. They contain empty, air-filled chambers which amplify the sound they generate, much like a resonance chamber does.
- Male cicadas have a special structure called a tymbal that they flex in order to make noise. That, combined with the empty cavities, creates the extreme volume of noise they can produce.
- The large number of cicadas, making noise at the same time, also contributes to the extreme volume.
What are common types of cicadas?
In the United States, there are two main groups of cicadas that you might come across: periodical cicadas and dog-day, or annual, cicadas.
The periodical cicada is exclusively native to North America, not found anywhere else in the world, and are typically found along the east coast. Periodical cicadas are most well-known for their life cycles, which take 13 or 17 year s for the nymph to grow and develop into an adult . Of the six species, three have 13-year life cycles while the other three follow 17-year life cycles. Often, this comes down to geographical location with 13-year periodical cicadas occurring mostly in southern areas and 17-year periodical cicadas appearing in northern regions. Periodical cicada nymphs spend most of this life stage living in soil; when they are mature, they begin to burrow upward. Once on the surface of the soil, they’ll eventually shed an outer layer of skin before hardening, becoming darker, and their wings expand.
Because of their long life cycle, periodical cicadas are sometimes referred to as 17-year locusts, however they are not true locusts. The reason for this name is due to early American colonists. The se colonists had never seen a real locust but were familiar with biblical stories of locust swarms; when they saw many periodical cicadas emerging at the same time, they mistakenly labeled these insects as locusts.
As mentioned above, dog-day cicadas are more commonly referred to as annual cicadas. This is because, depending on the species, dog-day cicadas may appear once a year in the summertime, anywhere from April to mid-September, depending on the location. Dog-day cicadas are smaller than periodical cicadas and are recognizable by the greenish veins that appear on their wings. Periodical cicadas, on the other hand, have orange-red wing veins. Like periodical cicadas, dog-day cicada nymphs also burrow underground but for notably less time. Dog-day cicadas have life cycles that are two to five years in length depending upon the species.
As you can tell, cicadas ar e interesting insects. There’s more to them than the tell-tale buzzing noise that they produce.