Water strider, pond skaters, skeeter, scooterskipper, pond skater, Jesus bug or Gerris spp.
Insects
Water striders are fascinating aquatic insects. They have many different common names, (including water skippers, pond skaters, skaters), and almost all of them refer to their amazing ability to walk on water! They are often observed on small streams, large puddles or ponds, or the edges of lakes and rivers, and some species even live on the salty ocean water!
Water striders are insects that belong to the family Gerridae. Many of their scientific species names have as the first part Gerris. Around the world there are over 1700 different species of water striders in this insect family.
Insects are the most diverse group of animals on our planet with over a million different species. You can know something is an insect if it has six legs (spiders are not insects – they have eight legs). Insects also have an exoskeleton, jointed legs, compound eyes and one set of antennae. They also usually have a body divided into three sections (head, abdomen and thorax), but there are some exceptions. Caterpillars are the larval form of many different types of adult insects.
Season
Water striders are found from early spring right through the fall. As with many insects a large number of the population will die after the breeding season. However, some adults will overwinter under logs and vegetation. These adults have wings and will fly back to water in the spring when the ice melts.
Interesting Facts
Most water striders are small, and like all insects, water striders have six jointed legs. Each leg has special hairs that repel water and help them to support their body on the surface tension of the water. Water surface tension is caused by the unique properties of water molecules. Surface tension is what causes water to form drops. Everyone (toddlers to grandparents), is mesmerized by watching water striders move across the water. The front and back legs don’t do much except keep the water strider steady. The middle pair of legs stroke backward as if doing breaststroke. It is these legs that propel the water strider forward. Interestingly, it turns out that water striders don’t actually “walk” on water at all; in fact, they jump. Their middle legs actually push back against the water and they leap forward, land and then coast to a stop. This can be seen in the following short video (https://thekidshouldseethis.com/post/surface-tension-water-strider). If water striders fascinate you, this other video is much longer and has more physics, but has some really interesting high speed video recordings (https://www.youtube.com/watch?v=_owbGh089kU).
Diet
Water striders are predators; they mainly eat other insects and spiders that fall into the water. They wait until something falls in; then they jump on it and then use their special mouth parts to inject special enzymes that digest the inside of the unlucky animal. Water striders will even eat their own young. Then they use other mouth parts to suck out the fluid that is the end product of this process. Water striders themselves are eaten primarily by birds, and occasionally by fish.
Mating
When water striders mate, they communicate with each other by using ripples on the water. A male will make a certain ripple. If another male receives this signal it will send out a “repel” signal. If a female receives the signal it will not send a return signal. The signaling male will then switch to a “courtship ripple”. Finally, the male will attach itself to the female for the entire reproductive season. The female will eventually lay eggs under the water and attach the eggs to plants or stones.
Biomimicry
Scientists inspired by the unique abilities of certain organisms often try and create inventions based on those unique abilities: this is called biomimicry. Scientists have created small robots which mimic the water strider’s ability to use the surface tension to walk and jump on water. These robots may one day be used to explore water surfaces.
~Monica Schuegraf
