Backswimmers: We are interested in all native wildlife including insects. Our ponds and dams have become home to a number of interesting and useful aquatic insects. There are more Backswimmers than any other visible organism in our water features. They are members of the Notonectidae family and there are about 30 Australian species. We appear to have two species in our ponds and dams.
Backswimmers, as with all insects, have six legs. They are about one centimetre long and have a streamlined body shape. Their abdomens have a keel along the centre line with hair-filled grooves on each side. The hairs retain air for breathing. Backswimmers breathe atmospheric air and must surface regularly to replenish their air supply. As the name implies they swim upside down. They are strong swimmers and use their long hind legs to speed through the water.
Backswimmers are carnivorous and prey on mosquito larvae and other small pond life. They are equipped with a piercing and sucking proboscis or beak. This beak is strong enough to pierce skin. We have experienced a Backswimmer driving its proboscis painfully into a thumb when collecting specimens for a university project. We now avoid physical contact with Backswimmers.
They breed in April and lay eggs in holes drilled in the stems of aquatic plants. The young mature in about five weeks after hatching. If the pond dries up then the Backswimmers have the ability to fly to other greener (or perhaps wetter) pastures. In our ponds and dams Backswimmers, because of their large numbers, are the principal means of mosquito control.
See Mosquito Control.