A Cicada Season Survival Guide
The drone of a cicada swarm is perhaps the most unmistakable, as well as unpleasant, sound of summer. 2021 is forecast to be an especially noisy summer, with the emergence of a large group of periodical cicadas known as Brood X. After 17 years of subterranean refuge, billions of cicadas will make their way above ground this May and June in the eastern and midwest United States. Those who remember Brood X’s most recent emergence in 2004 will regale you with stories of the insects blanketing lawns and buzzing incessantly. But in the few weeks that Brood X will emerge this year to mate and die, will the cicadas be anything more than just a noisy nuisance? Or do cicadas pose any serious threats to humans, our pets, or our homes? Here’s what you need to know in order to survive cicada season.
Can cicadas bite me?
The intimidating size and sound of cicadas often lead people to assume that these creatures have a bite that matches their bark. However, insectophobes will be relieved to learn that cicadas don’t have jaws, making them incapable of biting. Cicadas also lack stingers, poison, or any other dangerous anatomical features. Cicadas are not dangerous to humans or pets.
Furthermore, a cicada’s diet consists solely of tree sap, which means that they do not prey on other insects or animals.
But if cicadas don’t have jaws, how exactly do cicadas eat? Technically, cicadas drink rather than eat. Instead of jaws, cicada mouthparts consist of a stylet, or a straw-like structure that allows them to pierce plants to drink tree sap. Think of a boba straw piercing a bubble tea lid to suck up tapioca pearl goodness.
Can cicadas damage my garden?
Cicadas’ inability to bite makes them almost universally harmless (spoiler alert: cicadas will leave your vegetable garden alone). Read on for a more technical explanation.
Xylem, which is the fancy scientific term for tree sap, is plant vascular tissue that transports water and nutrients from the roots of the plant to the leaves. Adult cicadas drink xylem from branches and twigs, while nymph (ie young) cicadas drink xylem from tree roots. In order to access the xylem, cicadas use the tip of their stylet mouthpart to pierce the tree branch or root. However, cicadas’ saliva is thick and polymerizes upon contact with plant tissues, so it plugs up the hole it created and prevents the root from leaking xylem. This negates any damage inflicted on the plant from the cicada’s munching.
Slightly more likely to cause damage to plant life is the ultimate result of a brood’s emergence: egg deposition. Female cicadas cut small slits in plants to deposit their eggs. This is called oviposting. Worst case scenario, ovipositing can cause branches to wilt and die, but this occurs mainly in young or unhealthy trees, which you’ve probably been procrastinating trimming down anyway. Branch flagging is more of a cosmetic defect than a functional one for healthy plants. Keep in mind that cicadas are not the only creatures that can cause branch flagging; sap-feeding beetles and fungi are also responsible for cosmetic defects in plants, and can be significantly more difficult to eliminate than cicadas.
If you’re concerned about cicadas causing damage to your trees, or simply want to keep them off of certain plants, you can cover the plants in mosquito netting or cheesecloth. Don’t use insecticide; think of keeping cicadas off of your plants as more of a preventative measure and less of a defensive one. Insecticide use can end up damaging the plants you were trying to protect, or can make animals sick.
Can cicadas damage my property?
No; if cicadas wind up in your home, they likely won’t survive long enough to do any damage (if you keep your maple syrup supply locked up, that is). Resourceful homeowners faced with a small cicada infestation should recruit their four-legged friends to hunt down and eat the insects. Your pets will happily oblige; biologist Gene Kristsky likens an animal’s view of cicada emergences to the human equivalent of the emergence of “thousands of flying Hershey’s Kisses”. Cicadas are a high-protein, low-fat snack that’s safe for consumption by both animals and humans alike.
Cicadas and other insects are a regular component of people’s diets in many parts of the world. American chefs and scientists are trying to normalize cicada consumption in the US, where westernization views insects as pests as opposed to food. Some predict that by marketing insects as a sustainable protein source, the US will slowly begin to adopt insect consumption over the next several years. Entomologist and American Association for the Advancement of Science (AAAS) policy fellow Jenna Jadin points out that cicadas are arthropods, just like crawfish, crab, and shrimp, and even offers recipes and wine pairings for enjoying the insect.
Or, if you’re too squeamish to try Budget Lobster, you can kill a small cicada infestation by dropping the insects into a bucket of soapy water. Do not use insecticide, as most insecticides are not intended to be used inside the home.
Can cicadas damage my hearing?
This is the one area in which cicadas can cause potential harm. The reason why periodical cicadas emerge (in the case of Brood X, every 17 years) is to mate. Cicadas’ incessant screaming is actually a love song, produced by male cicadas with the goal of attracting a female mate.
Because cicadas have no biting jaws, poisonous stingers, or anything to give them a fighting chance of surviving individually, cicadas’ only chance at survival during emergence is to overwhelm their predators by sheer numbers. The population size of the emerging brood must be large enough to outweigh the inevitable casualties of cicadas that get eaten by birds and other predators. As a result, the mating call of one male cicada is multiplied thousands of times over, resulting in a blaring scream that can reach over 90 dB. Hearing damage can occur at about 90-95 dB, which is about the same noise level as a running motorcycle engine. Keep in mind that hearing damage at this level can occur only after prolonged exposure (~1 hr). If you need to raise your voice to be heard at arms length, chances are that the noise level is at least 85 dB, which can damage your hearing over prolonged exposure.
If you find yourself in a situation where cicadas are excessively noisy, you can wear earplugs or noise-cancelling headphones.
Cicadas Are Friends…And Food
Overall, cicadas are harmless insects capable of little more than bumbling around in search of the nearest maple syrup-rich tree branch. They are not dangerous to animals or humans, and they pose no negative environmental impact. In fact, they enrich the environment by pruning weak tree parts, aerating soil, and fertilizing the soil with their own nutrients when they die.
Summer 2021 marks the reopening of many outdoor activities as COVID cases dwindle in most US states. Don’t let Brood X chase you back inside; they’re probably just as excited as you are to emerge from hibernation.