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Friday, May 11, 2001


Water scorpion

*Japanese name: Kooimushi *Scientific name:Diplonychus japonica *Description: Water scorpions are aquatic insects that look a bit like beetles. They have wings, but they don't have the protective shell that beetles have. Their mouthparts are also unlike beetles: They have a sharp beak that is used for feeding. Their mid- and hind-legs are flat and broad like oars, and fringed with hairs to improve swimming ability. The forelegs are strong and sharp, and are used for catching prey -- and for biting your finger if you're not careful. Water scorpions have a special pair of breathing tubes that poke out of the end of their abdomen. The insects push these through the water surface when they need more air. Adults are 17-20 mm long.

* Where to find them: In wet rice fields and shallow ponds and swamps from May to October. They sometimes fly between ponds when the ponds are too crowded or when food runs out.

* Food: Small fish, frogs and shelled aquatic animals such as snails. Using their beak, water scorpions inject their prey with a special enzyme that turns their insides into liquid. Then they suck out the juice.

* Special features: Male water scorpions look after the young. This is very rare in the insect world, because most male insects move on to other females after mating. Normally a male can't be sure which eggs he has fertilized, but in water scorpions, the female lays her eggs on the male's back, fixing them on with a special glue. The male takes great care to keep the eggs safe and moist. After about three weeks, the larvae hatch and emerge like aliens from their eggs.

Enzyme: A protein that speeds up chemical reactions in animals.

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