Why do mosquito legs detach so easily?

Smacking them tends to destroy the parts that keep their legs attached to the body. And since they’re dead, their bodies also can’t send any signals to release their tarsal claws (which is what allows them to grip onto all sorts of surfaces, including walls and ceilings). So the legs might be stuck to whatever they were standing on.

I like @JeSuisRickSpringfield explanation and, also, considering we are like a gazillion times larger than a Mosquito, well, kinda like a Megalodon shark trying to pick us up by the leg after we have been crushed like a Mosquito, legs probably going to detach. haha

If you were smacked with at least a hundred times heavier and ten times bigger object that yourself, at full speed at that, do you think your limbs would stay in their place?

So they are left without a leg to stand on?

Mosquito glue (and legs) need to be pretty light in order for those things to retain even the limited aerodynamic qualities that they do retain. Besides, how close is your examination? Are you sure that the legs are coming off at the hip joints (analogous hip joints, that is, since one presumes that mosquitoes don’t have bones and actual hip joints) or are the legs simply broken at whatever was the weakest part of the limb when the force was applied?

I’ll be watching for your white paper and lab results.

A human weighs about 30 million- 40 million times as much as a mosquito. A human smacking a mosquito, is like something with 10 times the mass of the Empire State building smacking a human.

I agree with @CWOTUS that it’s impossible to know if the legs popped off or just gave way at the weakest point. A mosquito’s stance pretty much guarantees that the legs will be broken.

It isn’t just when you smack them. If a mosquito lands on my arm and I carefully place my finger over some of her legs, after she is done sucking my blood she just flys away and the legs remain behind. If I do the same thing with another insect, like a bee or a housefly, she won’t be able to escape until I release her legs.

You should probably be directing horror movies. I’m thinking that you may have missed your calling.

Unintelligent design?

So, maybe you have it, @farmer.
The legs are dispensable to a satiated female mosquito, and she’s able to lay her eggs sans legs.
If her legs are mired in something as she feeds, she just fills up, flies off, and hovers until laying time.

My answer evolved because your details evolved. If you hold her leg down and she flies away without it, that’s because her wing power is greater than her need for landing gear.

@farmer Mosquitos are very fragile. Bees and houseflies are much more durable. So even if you are holding them down in the same way and they try to pull away with the same amount of strength, the mosquito will break before the bee or the fly does.

Yes, @JeSuisRickSpringfield. WHY is the question.

Why would mosquitoes evolve to be fragile. Have fragile legs?

It seems pretty obvious to me: the evolutionary path that mosquitoes followed (unlike, say, horseflies, which clearly developed in a different direction) is to make as light a touch as possible on the victim / host. The mosquitoes who can land and feed without detection have the best chance to live to sexual maturity, to reproduce and continue development along their own genetic line. In that sense, “lightweight and even detachable legs” would be pro-survival – at least in the niche that they have “chosen” to live.