Invasion of the Silence Breakers

By Vickie Foster, Volunteer

Their black, crinkly, bodies striped in bright orange, by the hundreds they emerge and begin their invasion, distinctive by their red, almost glowing eyes. It's not the script for a late night horror flick, but the emergence of periodical cicadas that begins this month.


This brood of cicadas emerges every 13 to 17 years. They differ from the cicadas that emerge every year from late June to August earning the name "Dog-day" cicadas. Dog-day insects are green with dark eyes and do their droning call in the heat of the summer. Periodical cicadas will begin to call as soon as they molt their shells and their exoskeleton hardens this month. Then males' will only make their noisy cacophony for a few weeks.


You may have noticed the Swiss cheese appearance of the ground in some areas where these cicadas have emerged. There is safety in numbers for the enormous army when they crawl out. Their numbers are so huge that birds and predators are swamped with more than they can eat of the bulging-eyed insects.


Periodical cicadas have a short above-ground life cycle. The males, who escape being a bird meal, congregate in bachelor choruses to attract females. Crawling out in early May, the females are brown and wingless. They shed their exoskeleton leaving the shells that you've probably seen clinging to trees and plants. Females hang around waiting for the males to emerge and call. Sort of Juliets waiting for their Romeos to serenade them. Once mated, females cut slits in the smaller branches of trees. Eggs are deposited in the slits and offspring hatch in six to ten weeks. The newly hatched cicada then find their way to the safety of underground burrows where they will stay for 13 to 17 years. A long time to wait for a few weeks in the sun.


Female cicadas can damage young trees with egg slits, but mature trees weather the encounter unscathed. If you are concerned about immature trees try protecting them with mosquito netting or cheesecloth tied over the branches and secured at the trunk.


The brood of periodical cicadas emerging now is a healthy, large batch. The air will be filled with their hum for several weeks. At least they won't be as loud as they were in the summer of 1998. That year both the 17 year and the 13 year cicadas overlapped. It was the first time since 1777 this happened and they created a memorable racket.