Cicadas make up a large family of insects, which encompasses over 3,000 species. With so much variety, it only makes sense that not all Cicada species are the same. However, all Cicadas have a few things in common, including their natural diet and life cycle. On the other hand, some species have short lifespans, while others can live for over a decade.
Some species also emerge frequently, while others are a rare sight to behold. Lifespan and emergence are the main factors we use to differentiate and classify different Cicada species. According to these criteria, all species fit neatly into one of the three following categories.
Annual Cicadas are the most common type, encompassing most of the species. Around 190 species of Annual Cicadas can be found throughout the US alone. But Annual Cicadas are common around the world, being present in almost all continents except for Antarctica.
They prefer tropical or temperate climates with high summer temperatures. You’ll usually spot them in places like forests and national parks where vegetation abounds.
Annual Cicadas appear every year during summer, hence their name. They have a lifespan ranging from 2-5 years. They are “annual” only because some adults of the species emerge every year. But the rest of the developing Cicadas remain hidden until their final molt.
To clarify, Annual Cicadas don’t live as winged insects for 2-5 years. They spend most of their lifetime underground as nymphs. There, they dig through dirt and feed on the fluids from plant roots. As they grow, the nymphs go through a repeated molting process.
They shed their outer skin to expand in size. Depending on the Annual Cicada species in question, the entire growth process takes around 2 to 5 years.
After the nymph completes its final molt, it’s ready to emerge from the ground and transform into an adult Cicada. Adult Annual Cicadas are 1.75 inches long on average. Most species have black and green-tinted bodies, black eyes, and greenish translucent wings. Despite having a 2-5 years lifespan, Annual Cicada adults emerge every year because their life cycles aren’t synchronized.
Like any other Cicada species, Annual Cicadas only live for a few months after emerging as adults. They spend the little time they have left looking for mates and reproducing. Then, females start chewing holes in tree branches, where they deposit the fertilized eggs.
When the eggs hatch, the young nymphs fall to the ground. They then dig their way down to hide and feed. And so, the cycle continues.
Periodical Cicadas are the rarest of the bunch. There are only seven documented species of Periodical Cicadas in the world. While Annual Cicadas inhabit almost all of the world’s continents, Periodical Cicadas are unique to North America. More specifically, they cover the eastern and midwestern areas of the United States. They can be found in areas with deciduous trees and shrubs.
Throughout the years, most broods have appeared in states such as Alabama, Arkansas, Connecticut, Delaware, Georgia, Illinois, Indiana, Kentucky, Louisiana, Maryland, Massachusetts, Mississippi, Missouri, North Carolina, South Carolina, Pennsylvania, and Tennessee.
Compared to Annual Cicadas, Periodical Cicadas have a much longer lifespan. They live for 13-17 years. Their incredible synchronicity is another distinguishing quality. In any location where they live, all the nymphs are developing on par with one another. They all reach maturity at the same time. They emerge from the ground simultaneously, and in great numbers. Sometimes, more than 1.5 million insects will emerge at once on a single acre of land.
Like Annual Cicadas, Periodical Cicadas spend most of their life underground in an underdeveloped nymph stage. Contrary to popular belief, Periodical Cicadas don’t just lay there in a dormant state. For 13-17 years, they spend their time feeding on the xylem fluids of plant and tree roots. They shed their exoskeleton every four years on average.
After they complete their long and slow growth cycle, they emerge in late spring to early summer. Adult Periodical Cicadas are just over 1 inch long. They have black, rounded bodies, and deep red eyes. Their wings are orange-tinted, and they cover a three-inch width when fully extended.
After they emerge and develop into fully-grown adults, Periodical Cicadas live for an additional few weeks to a few months. During this time, males congregate in large numbers to call for female partners. Both male and female members of these species die shortly after reproduction.
Proto-periodical Cicadas are a lesser-discussed group of Cicada species. Unlike Annual Cicadas, the Proto-periodical Cicadas don’t appear every year. But they’re also more common, and they emerge more often than the 13-17-year Periodical Cicadas. Due to their confusing nature, which distinguishes them from the other groups, these Cicadas deserve their separate category.
Most Proto-periodical Cicadas belong to the genus “Okanagana”. There are at least 60 Okanagana species found throughout North America. These species are common in both Canada, as well as the US. The lifespan of Proto-periodical Cicadas varies depending on the species. Some live for nine years, while others have 17-19-year lifespans.
Proto-periodical Cicadas emerge in large numbers in some years, but they are scarce or absent during others. Of course, like other cicadas, most of their life is spent as a growing nymph. But there seems to be some kind of synchronization going on, because Proto-periodical Cicadas don’t show up in large numbers year after year. There’s a cyclical pattern.
For example, in a given area where these Cicadas are present, they’re abundant for 4 out of 9 years. For the remaining five years, they’re either scarce or completely absent. These periods will vary depending on the species’ lifespan.
All Cicadas go through an incomplete metamorphosis cycle consisting of three stages— egg, nymph, and adult. While some species are longer-lived than others, all species spend most of their lifetime underground. After emerging in late spring or early summer, all Cicadas live for just a few weeks to a few months as adults.
However, despite their similar development and short adult lifespans, Cicadas have a major distinguishing characteristic. That’s the frequency of their appearance. Depending on how often or seldom they emerge, all Cicada species can fit into one of three categories.
Annual Cicadas are the most common. They have a short lifespan (2-5 years). They can be found everywhere on the globe, and they emerge every year in similar numbers. Periodical Cicadas are the rarest in the world, consisting of only seven species. All the adults in a given territory emerge once every 13-17 years like clockwork.
Last but not least, Proto-periodical Cicadas are somewhat of a combination of the two. They live between 9-19 years, depending on the species. They emerge in large numbers for a few years, and they’re either rare or absent in others.Cicadas