Don't tell me it's raining

December 13, 2018 8:01 AM

Insect pee: Ultrafast fluidic ejection from sharpshooters - Sharpshooters are agricultural pests that “suck” copious amounts of fluid from plants and spread Pierce’s disease which threatens California’s multi-billion agricultural industry. A single sharpshooter can ingest up to 300 times their body weight per day in xylem fluid making them extreme biological pumps. To prevent fluidic build-up, they constantly have to release droplet excrements before ejecting them in the form of “pee” at ultra-high speeds. These insects, nicknamed the "pissing fly," have left passersby wondering if it's raining.

WaPo: Bhamla and his colleagues recorded videos of two insect species, the glassy-winged sharpshooter and the blue-green sharpshooter, as they fed on the plant tissue bringing water up from the roots and then sent droplets of the liquid waste flying in the air. Whereas regular cameras record at about 30 frames per second, they shot at thousands of frames per second. Then they went frame-by-frame, calculating how many millimeters the urine moved per millisecond.

What they found was that the ejected droplets of urine achieved peak acceleration of about 200 meters per second squared, or about 20 times the acceleration of Earth’s gravity. That’s also about 20 times the acceleration of a cheetah, Bhamla observed.

posted by mandolin conspiracy (15 comments total)

What they found was that the ejected droplets of urine achieved peak acceleration of about 200 meters per second squared, or about 20 times the acceleration of Earth’s gravity. That’s also about 20 times the acceleration of a cheetah, Bhamla observed.

Now that's what I call pissing like a race horse.
posted by Strange Interlude at 8:16 AM on December 13, 2018 [1 favorite]

Does this mean a cheetah could achieve escape velocity?
posted by GenjiandProust at 8:34 AM on December 13, 2018

I wonder why the aphids aren't so bothered by getting their "pee" all over them? They have to fly too, from time to time.
posted by hat_eater at 8:35 AM on December 13, 2018

Super sharp shooters shootin' super sharp shots.
posted by poe at 8:45 AM on December 13, 2018

Don’t piss on my head and tell me it’s raining.
posted by cenoxo at 9:06 AM on December 13, 2018 [1 favorite]

That is really fascinating. Insects live in a real-life science-fiction world.
posted by Dr. Wu at 10:02 AM on December 13, 2018

I wonder why the aphids aren't so bothered by getting their "pee" all over them? They have to fly too, from time to time.
Just a guess, but maybe related to the fact that aphids feed on the much more nutrient-rich phloem fluid, and thus process less liquid than xylem-feeders?
posted by agentofselection at 10:17 AM on December 13, 2018 [1 favorite]

and spread Pierce’s disease

I see what you did there.
posted by rhizome at 10:19 AM on December 13, 2018

Don't tell me it's raining

It's raining.
posted by It's Raining Florence Henderson at 11:22 AM on December 13, 2018 [4 favorites]

Skeeter Pee is also an inexpensive, quick, easy to make, easy to drink, naturally fermented, lemon, hot-weather, thirst quencher!
posted by exogenous at 11:27 AM on December 13, 2018

Hummingbirds pee a lot:

Three remarkable hummingbird discoveries
Scientific American, 10/3/2011

A specialised diet of nectar also means that hummingbirds have to produce a lot of urine (note that they also drink a lot of water). A lot. In fact, the urine they produce every day might amount to anywhere between 56 and 149% of body mass (Calder 1979, Calder & Hiebert 1983). For comparison, the urine normally produced by a human in a day amounts to somewhere between 1.5 and 2.5% of body mass. This copious peeing means that hummingbirds are forced to expel a significant amount of the electrolytes their bodies contain: studies of Broad-tailed hummingbirds S. platycercus indicate that they need to replace about 14% of their sodium and potassium requirements every single day (Calder & Hiebert 1983).
...
If you’re wondering, yes, there are various images and videos online of peeing hummingbirds [YT video 1, video 2], but to be honest they don’t show anything particularly remarkable.

(YMMV, but I find it rather difficult trying to unzip and urinate in midair.)

Watching hummingbirds drink at our home feeders, they usually evacuate when they fly off, perhaps to lighten their flying weight.
posted by cenoxo at 11:59 AM on December 13, 2018 [2 favorites]

Does this mean a cheetah could achieve escape velocity?

Wouldn't help them any, even if they could - cheetahs never prosper.
posted by Greg_Ace at 12:27 PM on December 13, 2018 [5 favorites]

>IRFH: It's raining.

We can handle it.
posted by cenoxo at 12:32 PM on December 13, 2018 [1 favorite]

This is really neat.

But, also, who on earth has intuition for how quickly cheetahs accelerate? (Aside from gazelles, I guess?) 200 m/s^2 is very cool, but after traversing the full ~2mm sling length, it's still only going 1/25 as fast as a cheetah at top speed. In the bug pee vs. cheetah race, I'm betting cheetah, assuming the track is at least a few cm in length.

Last time I heard about glassy winged sharpshooters, it was from an entomologist who was convinced they would destroy the California economy in the late 90s. It seems like that didn't happen. I'm now quite curious to look into why.
posted by eotvos at 3:37 PM on December 13, 2018

Maybe they're hypersensitive to the same nicotinoids that are killing the bees nowadays.
posted by rhizome at 4:41 PM on December 13, 2018 [1 favorite]