(Author: Huang Qianfan, insect science author, original works, reprint please indicate that the knowledge is the power of WeChat public account)
Insects on the earth are all masterpieces of nature, and they have different skills, but no matter what kind of insects they are, they need to breathe air. Insects on land, breathing air is not difficult. Under the action of ventilation movement, air enters the insect's tracheal system from the valve (equivalent to the "nostril" of humans), and then into the microtrachea, which in turn transports fresh air to various tissues of the body. However, some insects live in the water when they are young, and some do not leave the water for life, and they have evolved a variety of underwater breathing methods.
(Ventilation movement of insects)
Life-saving snorkel
Do you know what mosquito larvae are called? Little mosquitoes, of course not! It's called Abode. In the summer, we can see the stalks at the water's edge, especially in the backwaters. In fact, the mosquito larvae are very short-lived, only ten days. How did they breathe underwater in just a dozen days? It turns out that the magic weapon that maintains its normal breathing is the snorkel generated at the end of the tail. Standing upside down under the surface of the water, the snorkel is extended to the surface of the water to breathe air directly. If oil is dripped on the surface of the water, once the oil droplets stick to the fine hairs of the snorkel, it can make it impossible for the widow to open the snorkel, causing it to suffocate.
(Scorpion bugs can stand upside down in the water and suck up air)
There is also an insect called the scorpion bug (also called the water mantis), which breathes in the same way as the widow, and the scorpion bug has two slender snorkels at the end of the abdomen, which cling to the aquatic plant, and when breathing, it hangs upside down under the surface of the water and breathes air.
Thief who steals the air
Some insect larvae and pupae live in extremely oxygen-starved bottom silt, and their valves evolve into spikes in order to survive. The role of spikes is to puncture the roots or stems of aquatic plants, thereby absorbing the oxygen carried by the plant. For example, the rice water elephant beetle, an invasive alien species native to the United States and Cuba, is the main target of its scourge is rice.
(Rice water weevil larvae grab air with rice)
The spines formed by the extension of the abdomen of the larvae of rice can pierce the rhizome of rice, grab air with rice, and its adult insects can also eat rice leaves later, causing harm to agricultural production.
Take a bubble and go for a swim
The ability of aquatic insects is not only to absorb the air in the plant's body. The water-repellent hairs on insects can be used to store bubbles, so they can also breathe in the water with bubbles.
The dragon lice in ponds are common insects, and under its elytra, it stores air. Dragon lice breathe air in the bubbles through the abdominal valves. Whenever the oxygen in the bubble is consumed to a certain extent, the dragon lice will swim to the surface of the water, break the water film with the end of the abdomen, and replace the fresh air.
(Dragon lice will change to fresh air)
However, some aquatic insects can also not breathe on the surface of the water, but by collecting bubbles emitted by aquatic plants to replace the supplementary oxygen.
I have gills, but I'm not a fish
There are also insects (such as the larvae of ephemerals, dragonflies and stone silkworm moths) that rely on tracheal gills to breathe in the water. The tracheal gills are hollow, thin-walled filamentous or flaky structures. This structure can be distributed anywhere in the head, chest and abdomen of aquatic insects. Some insect larvae have more than 500 tracheal gills distributed on their bodies. In water, insects with tracheal gills swing their gills to allow the water to flow and suck up oxygen from the water. In oxygen-starved water, the frequency of the gill flap swings increases.
(Dragonfly larvae also have gills)
The tracheal gills of the dragonfly larvae are distributed in the rectum of the body, and by contracting the abdomen and allowing water to enter the body, the tracheal gills can absorb oxygen from the water. In order to ensure an adequate supply of oxygen, the dragonfly larvae renew 85% of their moisture each time they collect their abdomen. The process of each update is the process of cleaning the gills in the rectum, which is conducive to the dragonflies to keep the gills clean and facilitate the absorption of oxygen.
A skill that all aquatic insects share in common is breathing with body walls. When breathing with the body wall, the insect can pass through the body wall and exchange the oxygen in the water directly with the insect's body, which includes the absorption of oxygen and the discharge of carbon dioxide.
In winter, insects are less active and have low metabolic levels, and they can sustain life as long as they breathe with the body wall. When summer comes, insect life activities are more active, and it is necessary to take measures that use both body wall breathing and other breathing methods such as tracheal gills.
Editor: Liu Weiqiong
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