Billions of noisy bugs to take East Coast by storm for the 1st time in 17 years

[Buster's Uncle]

Billions of noisy bugs are about to take the East Coast by storm for the first time in 17 years
Business Insider
Ali Sundermier  Apr. 23, 2016, 1:30 PM



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You’ll hear them from a mile away. This spring, billions of cicadas will come up from underground, creating a symphony that the east coast hasn’t heard since 1999.

Cicadas are large, clunky insects with translucent wings and wide set eyes. They are divided up into different broods, or year-classes, based on when they emerge. There are twelve broods of cicadas in total. While some broods come to the surface every 13 years, most of them take 17 years. Think of it like high school. Only instead of having a reunion every 10 years, these rambunctious bugs get together every 13 or 17 years. And every 221 years, a brood of 13-year-old cicadas and a brood of 17-year-old cicadas co-emerge, bringing twice the fun.

These particular cicadas are Brood V. They spend the first 17 years of their lives underground, feeding off of plant roots. And over the next few weeks they’ll finally emerge.

Scientists think these super long hibernations might be an evolutionary tool the bugs developed to avoid predators. By coming out all at once, they essentially flood the market on cicada meat. Birds and other predators would have a hard time making even a dent in their population.

After spending their first week above ground as wingless nymphs, the cicadas will grow into adults, ready to slip out of their exoskeleton (leaving behind a menacing brown shell) and find a mate. And that telltale roar of clicks is their mating call.

So how do these tiny winged romeos produce a chorus that would rival the sound of a thousand rattlesnakes?

By rapidly vibrating their tymbals, of course.

Not to be confused with cymbals, tymbals are membranes in a cicada’s abdomen. When a male cicada buckles its body (at a rate of about 400 times a second) the tymbal vibrates, producing the buzz of insect love. And since its abdomen is almost hollow, its body works like a resonance chamber, amplifying the noise so that the sound of the cicada's good vibrations is broadcast across entire neighborhoods.

If the female cicada likes what she hears, she’ll respond by snapping her wings, an invitation for the males to move closer. The rest is history.

But this love story isn’t without its tragedy. Two to four weeks after emerging, the male will die, leaving the female alone to lay hundreds of eggs. Six weeks later the eggs will hatch, giving birth to the next generation of nymphs who will promptly burrow back underground.

And so ends the song of the cicada — for another seventeen years.


http://www.businessinsider.com/billions-of-cicadas-are-about-to-take-the-east-coast-by-storm-2016-4

[Unorthodox]

Getting really sick of these popping up every other year. 

The level of wrong in that particular piece is overwhelming. 

Cicadas are large, clunky insects with translucent wings and wide set eyes. They are divided up into different broods, or year-classes, based on when they emerge. There are twelve broods of cicadas in total. While some broods come to the surface every 13 years, most of them take 17 years. Think of it like high school. Only instead of having a reunion every 10 years, these rambunctious bugs get together every 13 or 17 years. And every 221 years, a brood of 13-year-old cicadas and a brood of 17-year-old cicadas co-emerge, bringing twice the fun.

There are 23 broods of periodic cicada.  The reason for 13/17 is specifically to avoid the competition as much as possible. 

MOST cicadas are actually annual cicadas, not periodic. 

[Buster's Uncle]

I've started avoiding Mic, on the grounds that the 'science' in the 'science' articles is not aiming very high - but the stuff Business Insider reprints is usually fairly solid.

Striking bug pic here, at least...

[Unorthodox]

Striking bug pic here, at least...

Other than that would be a brood 19, 22, or 23 pic since it's a Magicicada neotredecim or Magicicada tredecim (they are very hard to tell apart without magnification, the clear orange markings on the underside are a dead giveaway it's one of them though).  Not that I would expect anyone outside an entomologist to know that, so random stock photo to the rescue. 

[Buster's Uncle]

I said striking, not good...

[Lorizael]

Fun fact: the prime life cycle periods of cicadas are currently a hot topic in the philosophy of math.

[Buster's Uncle]

I kinda understood your blog article about that...

[Lorizael]

I wrote that post before I had any idea it was currently relevant (in the last 10 years or so) to philosophers.

The debate goes like this: naturalists think we should only believe things are real if they feature in our best scientific theories. Mathematical realists argue that because math features in our best scientific theories, math (that is, pi and triangles and imaginary numbers) must be real in some sense. Mathematical nominalists think that math only shows up in scientific theories as a kind of shorthand and that you could rewrite the laws of physics without using math, which means math isn't necessarily real. (Some philosophers are actually engaged, with some measure of success, in reframing physics in a math-free way.)

Cicadas are a counterargument. That is, number theory plays an essential explanatory role in why cicadas have prime number life cycle lengths, so mathematics is indispensable to science, so mathematics is real. Nominalists have tried to counter this example by claiming that it is begging the question (prime number life cycles only require explanation if you have theorems about prime numbers) and the debate rages on.

(When I talk about mathematics being "real," btw, what I mean is that mathematical objects are taken to be abstract, mind-independent entities rather than something humans just came up with to help do taxes or calculate tips (bistromathics).)

[Unorthodox]

How does the fact that most cicadas don't have prime number life cycle lengths play into the argument?  Or the (unknown cause) year deviations on that life cycle (early or late by up to 3 years)? 

[DrazharLn]

I guess more obvious mathematical stuff in nature like golden ratios can be explained math free, but primes are considered impossible to explain without maths?

[Lorizael]

How does the fact that most cicadas don't have prime number life cycle lengths play into the argument?

Most cicadas are apparently not employing a predator satiation strategy that involves synchronized emergence. Consequently, there is no evolutionary pressure to minimize the intersection between their life cycles and the life cycles of predators, and consequently no reason to expect prime numbers.

Or the (unknown cause) year deviations on that life cycle (early or late by up to 3 years)?

I think the theory is that emergence at 13 or 17 years is controlled by a single gene, so screw ups aren't unexpected. When the divergence is by a single year or so, there's some evidence that whatever biological counter cicadas are using to measure elapsed years can be tripped accidentally by early springs or something like that.

I guess more obvious mathematical stuff in nature like golden ratios can be explained math free, but primes are considered impossible to explain without maths?

The cicada example is definitely not the only one used to show that math is ineliminable to science. Another common example is the reason why honeycombs built by bees have hexagonal shapes. The key for both examples is the idea that some mathematical theorem (from number theory, or from geometry) helps explain why a particular thing happens in nature. Mathematics being explanatory is why some philosophers think it is essential to science. There are other examples of geometric designs in nature that might not necessarily explain anything.

Further, when philosophers ("mathematical nominalists") talk about "science without numbers," what they generally mean is something along the lines of... showing that a particular galaxy is 10 million lightyears away does not really require numbers. Units are arbitrary, so what's really significant is that the galaxy is far enough away to only be so big in the sky, or something like that. Putting numbers to it all might be useful but is not essential.

[DrazharLn]

Cool. Thanks.

[Unorthodox]

How does the fact that most cicadas don't have prime number life cycle lengths play into the argument?

Most cicadas are apparently not employing a predator satiation strategy that involves synchronized emergence. Consequently, there is no evolutionary pressure to minimize the intersection between their life cycles and the life cycles of predators, and consequently no reason to expect prime numbers.

This would only work if their predators also had life cycles longer than a year, or better yet, also prime numbers. Besides, several insects practice predator satiation on an annual basis with mass synchronized hatchings, there's no need to look at these odd cases for that.

Most cicada predators have annual life cycles and are able to live off the annual cicadas that emerge every year in the (rather few, honestly) years a periodic cicada hatch doesn't happen.  Considering the number of broods and the staggered emergence of them, most years have a periodic cicada hatch (though some localized areas can go years without). 

IMO, it's far more likely the prime numbers are to prevent crossbreeding between the broods than it is as a predator satiation tactic.  IIRC, it's something like once ever 221 years broods would run into each other. 

[Lorizael]

Yeah, preventing hybridization, which could smear out emergence times and reduce the effectiveness of predator satiation, is also a proposed explanation. For some reason, biologists think both factors play a role. I'm honestly not sure what has led them to that conclusion.

[Buster's Uncle]

...I've never seen anyone know enough about something in entomology to hang in there with Uno this long...