from Hacker News

How mosquitos deal with getting hit by raindrops

by davi on 6/25/15, 3:37 AM with 79 comments

• by developer1 on 6/25/15, 4:59 AM

  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

• by upofadown on 6/25/15, 1:52 PM

  >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.

• by dgemm on 6/25/15, 6:50 AM

  > But because our mosquito is oh-so-light, the raindrop moves on, unimpeded, and hardly any force is transferred. All that happens is that our mosquito is suddenly scooped up by the raindrop and finds itself hurtling toward the ground at a velocity of roughly nine meters per second, an acceleration which can’t be very comfortable, because it puts enormous pressure on the insect’s body, up to 300 gravities worth, says professor Hu.

  Interesting article, but in the span of one paragraph here we have confused velocity, acceleration, and pressure - and there are similar errors in the following one. For an article about physics, I would expect this to at least be proofread.

  The Gell-Mann Amnesia effect: http://harmful.cat-v.org/journalism/

• by daniel-levin on 6/25/15, 9:39 AM

  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. There are more than six species of mosquitoes. They controlled for wind effects (which are part and parcel of rain). So they excluded horizontally travelling raindrops. My immediate reaction to the conclusion that mosquitoes can fly in rain was "Really? Not always". Here is a methodologically lacking and wholly unscientific anecdote: I have lived in Johannesburg my entire life, where mosquitoes are quite prevalent during the summer months. When it is raining heavily (it is usually quite windy as well), the local species of mosquito that feeds of humans do not present a problem as the number of airborne mosquitoes tends to zero.

• by nippoo on 6/25/15, 12:40 PM

  "Had the raindrop slammed into a bigger, slightly heavier animal, like a dragonfly, the raindrop would “feel” the collision and lose momentum. The raindrop might even break apart because of the impact, and force would transfer from the raindrop to the insect’s exoskeleton, rattling the animal to death."

  Has anyone actually done any research on dragonflies being hit by raindrops, or is this just speculation?

• by chrismorgan on 6/25/15, 7:54 AM

  The drawings in this article tend to be absurdly large, with the outcome that the document is, transferred, around 23MB, for no good reason. Sigh.

• by Kiro on 6/25/15, 9:23 AM

  > In most direct hits, Hu and colleagues write, the insect is carried five to 20 body lengths downward

  > If you want to see this for yourself, take a look at Hu’s video

  What? Nothing like that happens in it.

• by ebbv on 6/25/15, 1:48 PM

  If it wasn't for the cute child like drawings this would be a truly terrible piece of link bait. As it is it's still pretty and, and I expect better from NatGeo.

  Anyone who lives in a mosquito heavy area knows that mosquitos (like almost all airborne insects) go into hiding during heavy rain and/or wind.

• by jbert on 6/25/15, 7:22 AM

  Does this places a reasonable selection pressure on the kinds of flying insects we can have?

  Big enough to shrug off a raindrop hit, or small enough to surf along the surface tension until it can slide off?

• by theVirginian on 6/25/15, 5:02 AM

  It would appear they haven't yet evolved to deal with being hit by cars quite as gracefully.

• by rokhayakebe on 6/25/15, 6:23 AM

  I just realized how making things fun and funny can help to teach anything. The drawings and the comical tone made this seem so approachable. I wish they had a series of 1000 of such lessons I could read.

• by jokr004 on 6/25/15, 5:47 PM

  Not really important but.. "nine gravities (88/m/squared)"

  I don't get it, the scientificamerican blog that they are quoting has the right units, where did they come up with this?

• by mordrax on 6/25/15, 8:29 AM

  > But because our mosquito is oh-so-light, the raindrop moves on, unimpeded, and hardly any force is transferred.

  So if the mosquito's weight is insignificant compared to that of the heavier and denser water drop and that's what keeps it from having the force transferred, would this equally apply to hailstorms? (Where our mosquitoes are pelted by small hail balls the size of raindrops)

• by mleonhard on 6/26/15, 1:35 AM

  The article embedded a short video. Here's longer video with explanations: https://www.youtube.com/watch?v=LQ88ny09ruM

• by state on 6/25/15, 4:38 AM

  Can't help but immediately notice: "Drawing by Robert Krulwich"

• by dharma1 on 6/25/15, 11:30 AM

  if you like watching slo mo videos, recommend this channel: https://www.youtube.com/user/theslowmoguys/videos

• by bnolsen on 6/25/15, 9:16 AM

  so if mosquiotos are oblivious to rain is there some way to make artificial rain with different properties that could destroy mosquitos en masse?

• by stillsut on 6/25/15, 2:31 PM

  Send this to Bill Gates, that guy HATES mosquitoes.

• by cJ0th on 6/25/15, 4:49 PM

  very interesting article. It is a pity that his column has no rss feed.

• by blumkvist on 6/25/15, 8:10 AM

  A commenter on the site says that some type of mosquitoes (Texas) are used in oil drilling. I tried googling "texas mosquitoes oil drilling" and variants, but didn't find anything.

  >"Why, one species even secretes an enzyme to dissolve the organic matter in blood leaving only the iron in haemoglobin. Then another enzyme causes the iron atoms to join to form biological drill pipe! These structures are known to be as much as 6 inches in diameter and to extend a mile deep."

  Is there something to it or he just went to on the internet to tell lies?