The insect commonly known as the pond skater, water strider, or water bug belongs to the family Gerridae, a group of true bugs adapted to life on the water’s surface. These slender, long-legged creatures are a familiar sight on still or slow-moving bodies of water, including ponds, lakes, and rivers. They glide effortlessly across the surface film without breaking the water tension. This is achieved through specialized legs covered in thousands of minute, non-wetting hairs that repel water and distribute their light body weight. Pond skaters utilize the molecular forces of surface tension to remain buoyant, moving atop the water’s surface film.
Primary Food Sources
Pond skaters are opportunistic predators and scavengers, feeding almost entirely on other insects and small invertebrates. They primarily consume terrestrial insects that have fallen onto the water surface and become trapped by the surface tension. This includes common flying insects like flies, midges, and mosquitoes, which cannot escape once they contact the water film. They also eat the larvae of aquatic insects that rise to the surface or small aquatic organisms that venture too close.
Pond skaters frequently scavenge dead or dying organic matter floating on the water, as their diet is not limited to freshly caught prey. They remain on the surface and do not dive beneath the water to pursue food. This surface-dwelling strategy helps regulate the population of insects that fall into freshwater ecosystems.
Hunting and Capture Methods
Pond skaters locate prey by sensing vibrations transmitted through the water’s surface. When a struggling insect falls onto the water, it creates ripples that act as hydrodynamic cues. Specialized hairs on the pond skater’s sensitive legs allow them to perceive the slightest disturbance, pinpointing the location of the trapped meal.
Once prey is detected, the pond skater moves swiftly across the water using its middle pair of legs for propulsion, functioning like oars. The longer hind legs are used for steering and stabilization. The shorter, stout front pair of legs are adapted for seizing and grasping the prey upon arrival, minimizing the chance of escape.
Specialized Feeding Mechanism
After securing the meal, the pond skater uses its specialized feeding apparatus to consume the captured insect. Like all true bugs, they possess piercing and sucking mouthparts known as a rostrum, or beak. The rostrum is a sharp, hollow structure used to penetrate the tough outer cuticle of the prey.
The pond skater then injects powerful digestive enzymes directly into the prey’s body through the rostrum’s hollow channel. These enzymes quickly break down and liquefy the internal tissues of the meal. The pond skater then sucks up the resulting liquid solution, leaving behind only the empty exoskeletal shell. This process is known as external digestion.