Adult periodical cicadas have blackish bodies, red eyes, and 4 membranous wings with a gold, orange, or red tinge. They crawl and fly, but they do not jump. The mouthparts, tucked beneath the head, are like a small, sharp straw. The antennae are short, and there are 3 ocelli (eyespots) in addition to the 2 larger, compound eyes. Compared to annual or “dog-day” cicadas, periodical cicadas are smaller.
Adult males have a sound-producing organ that emits a loud, raspy call used to attract females. Adult females have a curved ovipositor at the lower end of the abdomen, used to insert eggs into slits in twigs.
Nymphs are tan or brownish, wingless, stout, with the front pair of legs specialized for burrowing in the soil and for clinging onto trees as they undergo their final molt into adults. Neither nymphs nor adults are capable of harming people.
Habitat and Conservation
The different species and broods of periodical cicadas all have a life cycle similar to annual cicadas, except instead of living as nymphs for 2–5 years underground, with some adults emerging every year, the broods of periodical cicadas live underground for either 13 or 17 years, and all of the same type in an area emerge to become adults the same year — in fact, the same week.
One trigger for emergence is when the soil temperature (as measured 8 inches below the surface) reaches 64 F. This often occurs after a nice warm soaking rain, usually in May, but possibly as early as late April or as late as early June. Scientists are still trying to learn how cicadas synchronize their life cycles (over so many years!) so exactly.
When will Missouri see periodical cicadas again? Here are some predictions. Remember that the different broods may be present in some parts of Missouri but not in others. (See the links at the bottom of this page for a trove of detailed information.)
- Brood XIX (19) should emerge in 2024. It comprises 4 species of 13-year cicadas.
- Brood XXIII (23) should emerge in 2028. It comprises 4 species of 13-year cicadas.
- Brood III (3) should emerge in 2031. It comprises 3 species of 17-year cicadas.
- Brood IV (4) should emerge in 2032. It comprises 3 species of 17-year cicadas.
Periodical cicadas are one of the great wonders of nature, and they make a dramatic impact on our senses. Some people dislike the incessant din of calling males, while others are impressed by it.
Many human cultures have myths based on cicadas, and many people worldwide eat cicadas, too.
Periodical cicadas provide a temporarily huge, but not a perennial food source for their many predators.
The slits made in twigs by thousands of egg-laying females weaken branch tips, which often break off, providing a natural 13- or 17-year pruning mechanism. Young trees may be killed, however.
Birds feast on the plentiful cicadas and are probably the reason for their odd, simultaneous, abundant appearance. The huge numbers of cicadas overwhelm their predators’ ability to eat them up, so any individual cicada has a good chance of surviving and reproducing.
Cicadas that live long enough to succumb to old age, poetically enough, end up nourishing the soil, which was their “childhood home” for 13 or 17 years.
People often don't think about the great, cumulative importance of insects and other burrowing animals when it comes to aerating and mixing soil, and how their tunnels permit rainwater to soak into the ground.