THE LEAFLET

May 10, 2021 /
Jona Elwell

Cicada Resources

We wrote about cicadas way back in March, but now that their arrival is imminent, we wanted to share some of our thoughts and resources again.

Overall:

  • Trees are far more resilient than we think! Establishing and growing in a city is a tough job. Many trees survive and thrive in less-than-ideal conditions (compacted soil, sporadic watering, damage from bikes, pets, cars, and humans, disruption from construction). While cicadas aren’t a usual occurrence, trees are tough.
  • We do not recommend netting. Bird deaths and more non-recyclable plastic are worse than any minor damage cicadas may cause.
  • Post cicadas, most trees will be fine. But if your young tree looks rough, some minor pruning can set it right. Call us for a consult through our  Consultation program and we’ll take a look.

What they are:

  • Magicicada cassinii, better known as the cicada, are insects that emerge from the ground annually in the eastern United States. This year is Brood X’s (pronounced ten) 17-year life cycle is soon coming to an end. These nymphs have spent nearly two decades feeding on roots and will burst into a mating frenzy once the ground temperature reaches 64 degrees Fahrenheit.

When they’ll arrive

  • While there have been a few cicada sightings here and there, the swarm should arrive in large numbers by mid-May – but like most natural processes, that depends! The cooler weather we have had and will continue to have for the next week or so may delay the swarm’s arrival.
  • Once they come out of the ground, the cicadas should stick around for about a month before laying their eggs and dying off. The nymphs will return underground by August. Capital Weather Gang has a helpful graphic as part of their broader cicada coverage
emergence chart

Typical cicada emergence timeline. Photo copyright The Washington Post

What they do:

  • Cicadas are benign to humans (they do not bite or sting).
  • Although cicadas may cause minor damage to trees, they have a few benefits as well. The decomposing bodies of the adult cicadas will trap nutrients close to tree roots and act as a fertilizer. The tunnels created by the larvae will also act as a soil aerator.
  • This event is an awesome spectacle of nature that has made its way to the DMV. It’s truly an opportunity for millions of people to witness and enjoy a remarkable biological phenomenon in their own backyard that happens nowhere else on the planet!

What to do:

  • Smaller, young trees are the main concern. Once the cicadas arrive there is not a whole lot to do other than gentle shake your trees or brush the bugs off of their branches or leaves.
  • On mature, healthy trees even an increase of cicada activity should not concern you. Any damage to small branch ends will recover over time.
  • Post cicadas – if you notice a lot of damage to a young tree – it will likely self-correct.