Back Swimmers

(Family Notonectidae.)
These water bugs known as the "back swimmers" much resemble the water boatmen, but are very convex on the back and always swim with the belly upwards. This, in fact, distinguishes them from all other water bugs. In their habits they are much like the water boatmen. They are predaceous, and feed upon other water insects and even fish.

They are strong enough to master a good-sized minnow, and a prick from their beak is as painful as a bee sting. They carry below with them a greater air film than do the others, and have to hold fast with their fore legs to some stone or water plant to prevent themselves from popping up to the surface.

They are most active insects, and most interesting creatures for the aquarium. They hibernate in the mud at the bottom of streams, pools and ponds. The eggs are laid in the stems of water plants, which are pierced by the sharp ovipositor of the female. About two-thirds of the egg are pushed into the incision, and the remaining third is left extruding.

About a dozen species are known to inhabit the United States, and these are distributed in the genera Notonecta, Anisops and Plea.