How mosquitos deal with getting hit by raindrops • Hacker News Board

Re: How mosquitos deal with getting hit by raindrops

#61

Post by lfowles » Thu, Jun 25, 2015, 3:07 PM UTC

JTon wrote: post #54

upofadown wrote: post #53

>A study says a mosquito being hit by a raindrop is roughly the equivalent of a human being whacked by a school bus, the typical bus being about 50 times the mass of a person. That is not a sensible comparison. When you scale something mass changes as the cube of dimension. Strength changes as the square of dimension. So small things are inherently stronger with respect to their mass.

Thanks for the math to back up my own doubt. Fortunately, the bus analogy appears to be added by the author as a bit of sparkle and does not get brought up again.

I think it's a good analogy to have.

You don't have the same results from bus:human::raindrop:mosquito, but the size comparison is a useful measure. I didn't realize a raindrop was 50x the mass of a mosquito. I thought they were roughly the same size.

Further, it reinforces or introduces the idea (along with the conclusion of the study) that "So small things are inherently stronger with respect to their mass."

Lastly, this is National Geographic. Anecdotes and analogies are useful to communicate to the general public.

Re: How mosquitos deal with getting hit by raindrops

#62

Post by acyacy » Thu, Jun 25, 2015, 3:07 PM UTC

Dove wrote: post #59

acyacy wrote: post #49

Earlier quoted context omitted.

You find them in these areas. When it gets cold there tends to be far fewer of them. And compared to the equators its nearly incomparible.

Cold isn't required for hailstorms. The ice forms at altitude. We have a lot of hailstorms in the spring and summer in Colorado, and while it isn't the mosquitoiest place I've ever lived, there are mosquitoes.

Compared with where its mosquito haven like by the Equator?

I suppose raindrop vs hailstone is a reason is one of the reason's the density issues are so different.

Re: How mosquitos deal with getting hit by raindrops

#63

Post by phonon » Thu, Jun 25, 2015, 3:13 PM UTC

abandonliberty wrote: post #57

upofadown wrote: post #53

>A study says a mosquito being hit by a raindrop is roughly the equivalent of a human being whacked by a school bus, the typical bus being about 50 times the mass of a person. That is not a sensible comparison. When you scale something mass changes as the cube of dimension. Strength changes as the square of dimension. So small things are inherently stronger with respect to their mass.

[Citation Wanted] Very believable; how does the math work out?

https://en.wikipedia.org/wiki/Square-cube_law

Re: How mosquitos deal with getting hit by raindrops

#64

Post by daniel-levin » Thu, Jun 25, 2015, 3:30 PM UTC

soneca wrote: post #45

joeyspn wrote: post #38

Earlier quoted context omitted.

^This I live in a mediterranean zone near a huge lake and during summer mosquitos are your every night companions (specially if you're working during late night hours). But when a summer storm brews the mosquitos disappear for two or three days. Why? This has been for me a recurrent question, and the answer has been always obvious: few of them survive being hit by raindrops. You can make 1000 theories about how our t…

I also agree. > "And yet (you probably haven’t looked, but trust me), when it’s raining those little pains in the neck are happily darting about in the air, getting banged—and they don’t seem to care." I have looked and I don't trust you. I live in Brazil where mosquitoes are present all the time, even in the city (obviously, on a smaller scale than places closer to nature). I do notice that whenever is raining there…

Well, no, it's not empirical until we design some experiments to test the theory, make predictions, test them, come up with potentially observable data that would falsify our hypotheses, publish our results and let them be peer reviewed, reproduced elsewhere etc... The jump from anecdotes to empiricism is a large one that is not to be undertaken lightly.

Re: How mosquitos deal with getting hit by raindrops

#65

Post by omginternets » Thu, Jun 25, 2015, 3:31 PM UTC

upofadown wrote: post #53

>A study says a mosquito being hit by a raindrop is roughly the equivalent of a human being whacked by a school bus, the typical bus being about 50 times the mass of a person. That is not a sensible comparison. When you scale something mass changes as the cube of dimension. Strength changes as the square of dimension. So small things are inherently stronger with respect to their mass.

>That is not a sensible comparison.

Well yeah, since the mosquito evidently survives...

Re: How mosquitos deal with getting hit by raindrops

#66

Post by loisaidasam » Thu, Jun 25, 2015, 3:36 PM UTC

e2e8 wrote: post #6

developer1 wrote: post #3

Of course the video doesn't show anything interesting, the mosquito's leg is hardly even grazed. I was definitely hoping for the version where a drop smacked the insect dead on target. Fairly strange for a lab result - if that's the only video that was captured, it really doesn't seem to divulge much at all. Where's the cool video? :D

https://www.youtube.com/watch?v=LQ88ny09ruM

I was checking out that Andrew Dickerson dude's Youtube channel - https://www.youtube.com/user/andrew52987/videos - it's like a showcase for mosquito torture!

Check out this one: https://www.youtube.com/watch?v=8s1_f9fyjME

Re: How mosquitos deal with getting hit by raindrops

#67

Post by abduhl » Thu, Jun 25, 2015, 3:56 PM UTC

upofadown wrote: post #53

>A study says a mosquito being hit by a raindrop is roughly the equivalent of a human being whacked by a school bus, the typical bus being about 50 times the mass of a person. That is not a sensible comparison. When you scale something mass changes as the cube of dimension. Strength changes as the square of dimension. So small things are inherently stronger with respect to their mass.

This is slightly misleading - strength actually changes as the square of the dimension or the cube of the dimension, depending on which strength you're talking about.

Axial (tension, compression) and shear strength are derived from net area and so scale with by x^2. Flexural strength is derived from a factored second moment of inertia which happens to work out to x^3.

Re: How mosquitos deal with getting hit by raindrops

#68

Post by Dove » Thu, Jun 25, 2015, 3:56 PM UTC

acyacy wrote: post #62

Dove wrote: post #59

Earlier quoted context omitted.

Cold isn't required for hailstorms. The ice forms at altitude. We have a lot of hailstorms in the spring and summer in Colorado, and while it isn't the mosquitoiest place I've ever lived, there are mosquitoes.

Compared with where its mosquito haven like by the Equator? I suppose raindrop vs hailstone is a reason is one of the reason's the density issues are so different.

Yeah. Mosquitoes are densest in the tropics where hailstorms are rare, but just about everywhere on earth short of Antarctica has some mosquitoes. I'd think mosquitoes would meet hailstones occasionally, though I can't really see the mosquito surviving it.

Re: How mosquitos deal with getting hit by raindrops

#69

Post by Kluny » Thu, Jun 25, 2015, 4:27 PM UTC

stillsut wrote: post #55

Send this to Bill Gates, that guy HATES mosquitoes.

A man who thought, "When I'm a billionaire, I'm going to dedicate my life to getting rid of those nasty fuckers (mosquitoes)" and then did it.

Re: How mosquitos deal with getting hit by raindrops

#70

Post by DEinspanjer » Thu, Jun 25, 2015, 4:46 PM UTC

joeyspn wrote: post #38

daniel-levin wrote: post #35

From an io9 article on the same research: >> [Hu] and Dickerson constructed a flight arena consisting of a small acrylic cage covered with mesh to contain the mosquitoes but permit entry of water drops. The researchers used a water jet to simulate rain stream velocity while observing six mosquitoes flying into the stream. Amazingly, all the mosquitoes lived. The researchers used simulated rain drops on six mosquitoes…

^This I live in a mediterranean zone near a huge lake and during summer mosquitos are your every night companions (specially if you're working during late night hours). But when a summer storm brews the mosquitos disappear for two or three days. Why? This has been for me a recurrent question, and the answer has been always obvious: few of them survive being hit by raindrops. You can make 1000 theories about how our t…

I can't discuss how the rain interacts with the adults, but I have read scientific research that discusses how stagnant water is required for mosquitos to lay eggs and for the larvae to breathe. If the surface of the water ceases to be stagnant, the eggs cannot be laid and the larvae will suffocate.

I retrieved a link to an article last year that discusses a device that uses solar power to aerate ponds as a mosquito preventative [1].

A reasonable conclusions for the drop in population is therefore that two generations can be severely depopulated by a heavy rainstorm, leaving only the portion living in stagnant water that is sheltered from the rain and run-off to survive and repopulate.

1. http://www.wired.co.uk/news/archive/2014-05/19/mosquito-devi...