Where were you in 1996? When the Dallas Cowboys defeated the Pittsburgh Steelers to win the Super Bowl, Braveheart won the Oscar for Best Picture, and Alanis Morissette’s Jagged Little Pill won the Grammy for Album of the Year? If you live in the Northeast, particularly New York, Pennsylvania or Virginia you may also remember the cicadas. 1996 was the year the 17-year cicada last emerged, mated and laid eggs – the very eggs we are beginning to see re-emerge after 17 years of growth in the soil. Their extremely loud mating call is what they are usually known for, but these fascinating creatures have a very interesting life cycle.
Let’s back up a little. For those of you who may not know, there are two main types of cicadas – dog day cicadas and periodical cicadas. Dog day cicadas emerge every year and are typically green and black in color. Periodical cicadas emerge over a much longer period of time (anywhere from four to 17 years) and are typically red and black in color. The 17-year brood has the longest lifecycle of all the periodical cicadas, and 2013 is their year to emerge once again.
Here’s how it works. Back in 1996, cicadas of the 17-year brood emerged and mated. The females inserted and laid 400-600 eggs in the twigs near the end of the branches of hardwood trees and shrubs. The eggs hatched in about 6-8 weeks, then the nymphs dropped to the ground and entered the soil where they have been feeding on the roots of trees and plants for past 17 years. About two weeks before they emerge they will start working their way up the soil and typically emerge in the spring.
The entire brood in one area emerges at about the same time, generally in the tens of thousands. The emergence from the ground usually takes place in the evening. The nymphs climb the tree trunks, grasp on to the bark, shed their exoskeletons and become adults. The adults climb up the tree and then begin their courtship – and the loud, and often alarming, mating songs begin. The male mating calls for females make cicadas one of the loudest insects in the world.
Cicadas are relatively harmless – they feed on the sap from trees, and don’t bite. Unlike grasshoppers, which can be responsible for devastating crops, trees and plants, cicadas do not cause damage or feed on foliage. The adult cicada only lives for about four to five weeks.
How interesting that something can live in the ground for so long before it emerges! When you hear cicadas singing this year, remember they are harmless and appreciate that they really have something to sing about. Wouldn’t you after living in the ground for 17 years?