I grew up in the U.S. and we've always said that mosquitoes bite. It's true there are no teeth, but we think of a "stinger" as a separate body part, like the tail-tip of a hornet or scorpion. Especially since the mosquito is also feeding on us, we would definitely think of that as a "mouth" action -- hence "biting." It does make it hard to translate, though, if I'm thinking of one action but the correct expression in another language is not the same action! This seems to happen especially often with Japanese. Thanks for explaining the reason behind the expression.

http://j-town.net/fukuoka/research/results/197920.html http://j-town.net/tokyo/research/results/197921.html I say 蚊に刺されてかゆい／かゆか（Kumamoto dialect）. I live in Kumamoto in Kyushu. When I lived in Ube city in Yamaguchi prefecture, a woman said "蚊に齧<かじ>られた I was bitten by a mosquito". I was very surprised and asked her whether they say like that usually. Her answer was "Yes". Mosquitoes don't have teeth. （^-^） Female mosquitoes sting human beings and suck their blood.

蚊（か）に刺（さ）されてかゆいです。 か= mosquito さされる=to be stung by, stabbed by かゆい= itchy

In english, we say "I got bit by a mosquito" or "I have been bitten by a mosquito" Mosquitos don't sting :P