Get ready for what one University of Illinois entomologist is calling a unique biological phenomenon. Kacie Athey, a specialty crops entomologist at the University of Illinois, says we could see as many as one trillion cicadas emerge this year once the soil warms up to around 64 degrees.  The increase is due to two broods of periodical cicadas emerging after 13 or 17 years.  Athey says we usually only see one periodical brood emerge at a time.  But, this year there will be two, and that phenomenon hasn’t been seen since 1803.

The broods we will see are the Northern Illinois Brood along with the Great Southern Brood. The Northern Illinois Brood, according to Athey, will be concentrated in the northern part of the state along with parts of Wisconsin, Iowa and Indiana.  The Great South Brood is typically in the southern part of the state as well as other states.  She says there will be some areas in Illinois where there will be an overlap.

After years of living in the soil and feeding off tree roots, the broods will emerge, mate and then die.  Athey says the male cicadas will be responsible for the loud noise will measure around 90 to 100 decibels.  The emerging broods of periodical cicadas are in addition to our annual dog day cicadas. According to Athey, they are harmless to people and don’t bite, but they can be trouble for an orchard owner who has recently planted trees.