City of Lake Forest, IL

Lake Forest will be buzzing this summer with the hum of cicadas!

While they may be noisy, the cicadas are mostly harmless and their emergence is a natural cycle that’s beneficial for the environment.

Cicadas are a common occurrence annually during summer, but every 13 and 17 years, a periodical cicada emerges from the underground. The cicadas then will mate and lay their eggs in tree branches; the female will make a slit in small branches of trees. The female then lays her eggs in these slits before dying. Around four to six weeks later, the eggs hatch, and the young cicada nymphs fall to the ground, tunnel into the soil, and the cycle starts over again.



Cicada Management Best Practices: 

• Avoid planting young trees less than 2 inches in diameter this spring. Because the cicadas lay eggs in slits in small tree branches, multiple cicadas laying eggs in a young tree could cause its rapid decline. The City is limiting its spring parkway planting this year and has deferred many planting locations until the fall.
• Cover vulnerable small trees with netting.
• Avoid contact insecticides. Due to the large scale of the emergence, insecticides can be harmful to beneficial insects.

The City will not apply systemic or contact insecticides during the emergence to decrease the activity of the cicadas. Cicadas don’t bite or sting, and they aren’t poisonous. Enjoy this natural phenomenon!  

If you have any questions, please call the Forestry section at (847) 810-3564. 

Find more information on cicadas from the Lake County Forest Preserves.