Hobbies And Interests
Common Characteristics
All spring water bugs share certain common features. Unlike most other insects that make their homes near water sources, water bugs do not have gills with which to extract oxygen from the water. They breath air directly through two tubes located either on their head or their tail. All spring water bugs also have needle-like mouth parts they use to suck up the soft internal parts of their prey, which they have killed by injecting them with a toxin. Most feed on small aquatic animals and insects, but a few eat algae and vegetation.
Largest
The two largest species of spring water bugs are the electric light bug, named for its propensity to fly into electrical lights, and the giant water bug. Both can reach 2 inches in length and have specially adapted front legs that are used to grasp prey. Both types will attack small fish such as minnows, dragonflies, tadpoles and even frogs.
Surface Walking
The most commonly seen spring water bugs are those that ride on top of the water. Conspicuous among these are water striders and water skaters. These species have comparatively small bodies and long, thin legs with which they move across the surface of the river or lake where they live. Their slightness and the reach of their limbs means that they do not break the surface tension of the water--they use their limbs like oars to propel themselves. These limbs, while perfectly adapted for the aquatic environment, are almost useless on land.
Breeding
Spring water bugs, in common with their land-based cousins, lay eggs. However, water bug eggs spend their entire incubation period under water. While some species will deposit their eggs in the vegetation litter that forms on the bottom of the slow-moving water sources they prefer, or on the underside of surface plants such as water lilies, some are more conscientious parents. The male giant water bug, for example, carries the eggs on his back for their 6-day incubation (although sometimes only because the female has forcefully laid them there). This is for better aeration of the eggs as he moves around and for protection from predators. This second consideration also influences the female water boatman, who will sometimes lay her eggs on the back of a crawfish.
Diving
Most spring water bugs spend almost all their time on or near the surface of the water so that they can breath regularly. Some water bugs, however, such as the water boatman, dive under the water surface for considerable lengths of time. To do this, they trap a bubble of air under the waterproof hairs on their body. This air bubble works for the water bugs much like a scuba tank works for a human.
Swimming
Backswimmers are unique among spring water bugs because of their body orientation when swimming. They are prone to hang head-down from the surface of the water and always swim on their backs. Scientists believe this behavior maximizes the backswimmer's chances of seeing insects falling into the water from vegetation overhead.