Cicadas are often called locusts, but they really aren’t. Locusts are grasshoppers and belong to a different group of insects, along with crickets and katydids. Cicadas, on the other hand, belong to their own distinct group of insects. Despite this common misconception, cicadas and locusts are quite different in appearance, behavior, and life cycle. Right now, we have two kinds of cicadas making all the noise, and although they are the same genus, they are different species.
Currently, we see a slightly larger golden-brown cicada and a drab greenish one. Both of these species have white bellies, but their differences don’t stop there. The green cicada is known for its slightly higher-pitched song. Interestingly, only male cicadas sing, and they use this song to attract mates, adding a unique auditory backdrop to the summer season.
Types of Cicadas
There are two main groups of cicadas: annual cicadas and periodical cicadas. Both have fascinating life cycles, but they differ in their timelines and patterns of emergence. Annual cicadas, also known as dog-day cicadas, are the ones we hear during the hottest months of the summer, typically July and August. However, in particularly hot years, their calls can be heard in June and September as well. In fact, this year we started hearing them in the last week of June, marking the early arrival of their familiar summer serenade.
The Life Cycle of Annual Cicadas
Cicadas spend the majority of their lives underground as nymphs, feeding on the sap from tree roots. Annual cicadas, like the dog-day cicadas, remain underground for about three years before emerging as adults. Once they emerge, their primary focus is to mate and continue the species, which is why we hear them every summer. Although dog-day cicadas follow this three-year cycle, different broods emerge each year, ensuring that their distinctive calls are a constant presence during the summer months.
Once cicadas become adults, they no longer feed, as their life above ground is brief. Their main purpose during this short period is to reproduce. After mating, female cicadas lay eggs, and the cycle begins again. The nymphs hatch and burrow underground, where they will remain for the next few years before it is their turn to emerge as adults.
The Unique Periodical Cicadas
In contrast to the annual cicadas, periodical cicadas have a much longer life cycle, spending either 13 or 17 years underground as nymphs. When the time comes for them to emerge, it happens in massive numbers. These cicadas, often referred to as “broods,” emerge in the millions, creating a truly awe-inspiring spectacle. During the two weeks they spend above ground, periodical cicadas focus on mating, laying eggs, and then dying.
In Oklahoma, where we have 17-year cicadas, the last major emergence occurred in 2015. The next one is anticipated in 2032, an event that nature enthusiasts eagerly await. This long gap between emergences is one of the most remarkable aspects of periodical cicadas, as they live in near-complete isolation underground for over a decade before they reappear in spectacular fashion. When they do, the sheer volume of their calls can be overwhelming, as millions of male cicadas all sing in unison to attract mates.
The Role of Cicadas in Nature
Cicadas, despite their noisy reputation, play a vital role in the ecosystem. Their life cycles, whether annual or periodical, contribute to the health of the soil as their burrowing helps aerate the earth. Additionally, cicadas serve as an important food source for a variety of animals, including birds, mammals, and even some fish. When cicadas die, their bodies provide essential nutrients to the soil, further benefiting the surrounding ecosystem.
The emergence of cicadas is often seen as a sign of the changing seasons, particularly in summer. Their distinctive sound may be a source of annoyance for some, but it also signals the heat of the season and the cyclical rhythms of nature.
Cicadas are fascinating creatures with complex life cycles that vary between species. Whether you are listening to the annual dog-day cicadas or awaiting the next emergence of periodical cicadas, their presence is a reminder of the intricate balance of nature and the role even the smallest insects play in our environment. So, the next time you hear the loud, rhythmic hum of cicadas in the trees, take a moment to appreciate the remarkable journey these insects have undergone to bring us their summer song.
Cicada hole
