Is the water strider a pest, and why doesn't it fall into the water?
Summary: Is the water strider a pest? Why doesn't it fall into the water?
What is the spider-like insect floating on the surface of rural wells? I believe many friends have seen this kind of insect, not only in wells, but also often in other waters. In fact, its scientific name is the water strider (pronounced "min").
What is a water strider?
When I was a child, I often saw this kind of bug in ditches and lotus ponds. As a child, I loved skipping stones on the pond, and every time, this kind of bug ran especially fast and never fell into the water. Its legs kept gliding along, and sometimes it would even jump up. Here, we call this bug "water crawler." Back then, the adults at home would even scare children by saying this bug must not be caught, or you would get bitten. Thinking about it now, it was very likely just to keep mischievous children from playing by the water.
What kind of bug is the water strider?
The most distinctive part of this bug is probably its several slender, slender legs. Although its body is not big, its legs are indeed very long and very thin. It moves on the water surface as if on a mirror, with no need to worry at all about falling into the water. When I was little, I was somewhat afraid of this bug because adults said it would bite. Many people are probably very curious why the water strider, clearly an insect, can walk on the water surface without falling in.
Why doesn't the water strider fall into the water?
First, because the water strider's body weight is very light. A water strider weighs only about 30 milligrams, and there is a membrane-like substance on the water surface, so such a light water strider does not easily fall into the water. Second, the most critical part lies in the water strider's legs. Although the water strider's legs are very slender and curve out to both sides at about ninety degrees, this prevents the water strider's feet from breaking the water membrane. In addition, there are some small secrets in the water strider's legs. If you catch a water strider and put it under a magnifying glass to observe, you will find that its legs are covered with fine hairs. These hairs are hydrophobic, so when the water strider moves on the water surface, it does not need to worry that its feet will be soaked by water and cause it to fall in. It is precisely because of these special characteristics that the water strider has also become an important indicator for testing the degree of water pollution.
Water striders test water pollution
The principle of using water striders to test water pollution is actually very simple, because if surfactants such as dish soap increase in the water, the water strider will fall into the water because the surface tension of the water decreases. From the depth to which the water strider falls into the water, we can see the degree to which this body of water is polluted by surfactants.
Is the water strider a pest?
This mainly depends on the water strider's feeding habits. The water strider moves on the water surface and generally feeds on small bugs on the water surface, dead bug corpses, insect eggs, and so on. Sometimes it itself also becomes food for fish. So the water strider should be considered a bug that does no real harm.
This is Science Xingnong. You are welcome to add a follow and learn together.