Water bugs are familiar insects in aquatic habitats throughout the World. They belong to the order Hemiptera, the largest insect order with incomplete metamorphosis. There are basically two kinds: (1) the semiaquatic bugs (Gerromorpha) which live upon the water surface and (2) the true water bugs (Nepomorpha) which live beneath the water surface. Water bugs are found in a wide variety of natural habitats from small, temporary pools to larger ponds and lakes, from small streams to rivers, and from inland freshwater bodies to coastal mangroves, tidal pools of coral reefs, and the surface of the ocean. Water bugs are chiefly predators or scavengers, feeding on any prey they can master, from tiny crustaceans and insects to tadpoles and small fish. They play a major role in aquatic ecosystems and may serve as indicators of the biological quality of aquatic habitats. They are chiefly beneficial to man since many species prey on mosquitoes and are themself preyed upon by fish. Because of thei