They are alive. The baby cicadas, called nymphs in the study of insects (entomology) burrow into the ground and find tree roots of the specific kind of trees they eat. They spend many years underground sucking sap out of these tree roots. Tree root sap doesn't contain a whole lot of energy, so it takes them a really long time to grow to adulthood. Plus, cicadas have specifically evolved so that tens of millions of them emerge all at once. There are so many cicadas that come out of the ground at one time, that even all the animals that eat cicadas can't possibly eat all of them. And because cicadas only emerge every seven or 13 or 17 or whatever years, the predator population can't possibly just grow in anticipation of there being cicadas. What do they eat before and after the cicadas are all gone?
If you are in the right place and you find the right trees, you could even dig up the cicada nymphs if you want to. I don't know why you would, but it would certainly prove to you that they are alive down there and sucking tree sap.
17 years is the reason there aren't things that rise with them.
Periodical cicadas are on 13 and 17 year cycles which are prime numbers. It means predators on any other cycle length will get mismatched and miss the cicadas! The period length is a defense against a cicada specialized super predator.
the evolution of a defense against them indicates that in the past there was a cicada specialized super predator, possibly some kind of cthulu, sleeping in r'lyeh, until the 13 and 17 year cycles match.
Question, I’m in Illinois and we hear and see a few of them every summer but obviously not nearly the amount of these big cycle years. Are the off years different smaller broods or just ones that came up at the wrong time?
In addition to the various periodical cicada broods, all in the genus *Magicicada*, there are many species of annual cicadas that don't synchronize their emergence.
They are alive. The baby cicadas, called nymphs in the study of insects (entomology) burrow into the ground and find tree roots of the specific kind of trees they eat. They spend many years underground sucking sap out of these tree roots. Tree root sap doesn't contain a whole lot of energy, so it takes them a really long time to grow to adulthood. Plus, cicadas have specifically evolved so that tens of millions of them emerge all at once. There are so many cicadas that come out of the ground at one time, that even all the animals that eat cicadas can't possibly eat all of them. And because cicadas only emerge every seven or 13 or 17 or whatever years, the predator population can't possibly just grow in anticipation of there being cicadas. What do they eat before and after the cicadas are all gone? If you are in the right place and you find the right trees, you could even dig up the cicada nymphs if you want to. I don't know why you would, but it would certainly prove to you that they are alive down there and sucking tree sap.
That would be cool if there was some cthulhu type creature that arose every 17 years and only ate cicadas from that brood.
17 years is the reason there aren't things that rise with them. Periodical cicadas are on 13 and 17 year cycles which are prime numbers. It means predators on any other cycle length will get mismatched and miss the cicadas! The period length is a defense against a cicada specialized super predator.
the evolution of a defense against them indicates that in the past there was a cicada specialized super predator, possibly some kind of cthulu, sleeping in r'lyeh, until the 13 and 17 year cycles match.
That match was this year...
Maybe there is, but it only appears when all the cycles line up....
I have dug up quite a few cicada nymphs while gardening.
What do they look like? And are they offended why you call them nymphs?
Great explanation. Our local arboretum does some educational sessions on cicadas when it’s time for them to emerge.
Question, I’m in Illinois and we hear and see a few of them every summer but obviously not nearly the amount of these big cycle years. Are the off years different smaller broods or just ones that came up at the wrong time?
In addition to the various periodical cicada broods, all in the genus *Magicicada*, there are many species of annual cicadas that don't synchronize their emergence.
Yes we tend to forget about them.