It was every mosquito for itself on Sunday in Riceville, Iowa. The air raid siren wailed as the town's 930 people went out at dusk for their third annual "Mosquito Shoot-Out.". "We really took care of them," said Smitty Messersmith, editor of the Riceville Record and shoot-out organiser. He estima-ted that the massacre would keep the place mosquitofree for a week. Residents insisted that the clouds of insecticide floating over the town did not hurt anything but the mozzies. "It smells real nice," said one. "It can be used as bathroom deodorant in a pinch.