Periodical Cicadas

Habits

The majority of a 17-year cicada’s life is spent developing in an underground habitat. During this time, they feed on the juices of tree roots. After 13 or 17 years, periodical cicadas emerge from the soil when the temperature eight inches below the surface reaches 64 degrees. Once above ground, the adults may feed on plant juices with minimal damage from feeding; although, damage may occur from the female jabbing plants with a saw-like apparatus to lay eggs into trees or shrubs.  

After emerging from underground, periodical cicadas will remain above ground for about a month, during which time they will molt in leaves, copulate, and lay eggs in slits the females cut on the ends of small tree branches. Each female cicada can lay between 400 and 600 eggs, meaning populations can be enormous. The adults die off while the cicada offspring fall to the ground and burrow into the soil, until they re-emerge 13-17 years later. 

Periodical cicadas are least active at nighttime when they are most likely up in the trees, and early in the morning when the temperature is cooler. They are strong yet clumsy fliers, occasionally flying into objects that cross their paths. As a result, it is common for cicadas to unknowingly fly into homes if residents leave doors or windows open. Periodical cicadas are unable to breed indoors, so infestations in houses are not likely. 

Threats

Even though they appear in strong numbers, periodical cicadas are only considered nuisance pests. They do not bite or sting, and generally do not pose any health threats to humans. In general, the majority of complaints related to periodical cicadas are in relation to their noisy behavior, as well as their skin shedding. Cicadas are known as the loudest insect in the U.S., as their “singing” can be heard for up to ½ mile away. Additionally, 17-year cicadas can cause damage to young trees.