You’ve been hearing that Brood X cicadas are coming to New Jersey for a while now. But when exactly will they appear outside your door, how long will they hang around and what should you do if you’re having anxiety about a backyard invasion? We asked Dr. Jim Fredericks, chief entomologist for the National Pest Management Association about what we should expect when these noisy red-eyed insects re-emerge in New Jersey (and on your lawn).

New Jersey Family: The cicadas are returning to New Jersey after a 17-year absence. What does this actually mean for us? When are they expected to emerge in full force? 

Jim Fredericks: They will emerge over a two-month period across much of the state beginning in May 2021. The trigger for periodical cicada emergence is soil temperature eight inches deep. The soil temperature must reach 64 degrees Fahrenheit to trigger emergence. The emergence will be greatest in areas that have plenty of trees and experienced high levels of cicadas 17 years ago. It’s important to note that in areas that were forested 17 years ago, which are now shopping centers, parking lots or housing developments with young trees–cicada levels will be drastically reduced from 17 years ago. Cicadas spend 17 years developing underground feeding on the roots of trees.

NJF: Some of us are having major anxiety about cicadas swarming our backyards. How likely is this?

JF: Unlike pests such as bed bugs, termites or cockroaches, cicadas do not cause harm. They do not bite or sting and are unlikely to cause any damage to trees. It is understandable that some people may not like billions of bugs emerging all at once, so luckily for them, they will likely be gone by mid-July.

NJF: How should we be preparing for cicadas?

JF: No preparation is necessary, but if you decide to venture out for cicada watching, wear bug repellant to keep ticks and mosquitoes at bay. When you return home, do a thorough tick check. For more information about ticks and how to avoid them, visit Some young seedling trees could experience damage when cicadas lay eggs on young branches. If you have a very young tree you are concerned about, it can be covered with light netting to keep cicadas off.

NJF: What should we do if we see cicadas en masse in our yards?

JF: Cicadas emerge from the ground by the hundreds or thousands per acre in their nymph stage. Once above ground, they will shed their shells, which you may find discarded near trees or on the ground. Rake your lawn regularly and discard any left behind shells to prevent build-up.

In areas of high concentrations of cicadas, they can cause damage to very young trees when they lay their eggs on young tree branches. Protect tree saplings by covering them with netting or cheesecloth. Netting should have a mesh of no less than 1/4 inch and should be placed over the trees when the first male songs are heard. In late July, many trees will have some dead leaves appearing at the end of some branches, this is normal and will not be harmful to healthy trees.

NJF: What should our kids know about cicadas and what to do if they see them?

JF: While the emergence of billions of cicadas may be unnerving, they are harmless to people. This spectacle of nature only occurs once every 17 years, so be sure to also take a moment to enjoy this natural wonder while it lasts. Cicadas provide food for many animals, including birds, reptiles, snakes, and even spiders and other arthropods. When underground, the nymphs construct tunnels that aerate the soil and allows for roots to get more access to nutrients and oxygen for growth. The cicadas that emerge don’t live for very long and the large piles of cicadas that have died increase nitrogen in the soil that enhances plant and tree growth.

NJF: How long will they be around? 

JF: Just as quickly as they will emerge, Brood X cicadas will disappear. After spending 17 long years underground, these nuisance pests only live for a few weeks to mate and lay eggs. Six to 10 weeks after the adults die off, the nymphs will begin to burrow underground to feed and grow for nearly two decades. Above ground, cicadas only live for a few weeks and Brood X will most likely be gone sometime in July.

NJF: What can we do to prevent the Brood X cicadas from making their way inside our homes?

JF: Cicadas are clumsy fliers and have been known to fly into people or objects that cross their paths. As a result, it is common for cicadas to unknowingly land in your hair, get stuck on your clothes or fly into your home if you leave doors and windows open. Periodical cicadas, however, are unable to breed indoors, so an infestation in your home is not likely.

Cicadas will not harm you, but here are some tips to limit your interactions with cicadas and prevent them from entering your home:

      • Ensure your doors and windows have screens if you keep them open on warm days.
      • Carry an umbrella, wear a hat or keep long hair tied back when spending time outdoors.
      • Limit the amount of time you spend outdoors during the day. Cicadas are least active early in the morning when temperatures are cooler and during nighttime.

For more info about cicadas, head to