But the antidote is not a patent of human beings, and some animals also know how to use it. Today, let's see how ants use the antidote.
The first character in this paper is an invasive red imported fire ant native to South America. In the 1930s, imported red imported fire ants were inadvertently introduced into the southern United States, and quickly spread there, which made people have a headache. Invasive red imported fire ants have strong adaptability and can nest in various environments. Their nests often cause great damage to farmland, courtyards and even houses. Invasive red imported fire ants not only prey on various insects, but also attack birds and small mammals, causing great damage to the ecological environment. In addition, the invading red imported fire ants are extremely aggressive. If their nests are disturbed, worker ants will flock out, climb on human or animal bodies, grab the skin with their upper jaws, pierce the skin with stingers at the end of their abdomen and inject venom. People who are bitten by red fire ants will feel the pain of their skin like being burned, hence the name "fire ants". There will be swelling in the bitten area. Although these swelling will gradually disappear, some patients will have serious infection or allergic reaction, and some will even die. It is estimated that the United States spends as much as $5 billion a year on preventing and controlling invasive red imported fire ants and their bites.
An important reason why the invading red imported fire ant is so powerful is that it can secrete highly toxic venom. Although we have not fully understood the mechanism of action of the venom invading red imported fire ants, we have basically determined that the main components of the venom are various alkaloids. Alkaloids refer to a large class of organic substances containing nitrogen in organisms. The presence of nitrogen atoms makes the molecule alkaline, hence the name alkaloid. Many alkaloids are highly toxic, such as nicotine and morphine, as well as aconitine and brucine, which are highly toxic substances and make people look pale. In addition to alkaloids, the venom of imported Solenopsis invicta contains a lot of protein, and some protein may also be toxic, or help the alkaloids spread to the tissues of the bitten person.
Due to the strong invasion of red imported fire ants, the local native ants almost disappeared. However, decades after the invasion of the southern United States by red imported fire ants, a dramatic scene happened. Since the end of the last century, another protagonist of this paper, the yellow mad ant, which is also native to South America, has also been introduced to the southern United States. After the arrival of this yellow ant, which is smaller than the invading red imported fire ants, it quickly beat the invading red imported fire ants out of the water, and even the nest of the invading red imported fire ants was occupied by yellow mad ants. This phenomenon naturally aroused the interest of scientists. What secret weapon did the yellow mad ants use to defeat the invading red imported fire ants?
Researchers at the University of Texas in the United States carefully observed the living habits of the yellow mad ants, especially the competition with the invading red imported fire ants. They found that the yellow mad ants didn't go as far as the local ants. They often take the initiative to attack invading red imported fire ants and compete with them for food. In the face of the challenger, the invading red imported fire ants naturally sprayed venom on the yellow crazy ants rudely. Then, however, an interesting scene happened: the yellow mad ant bent its abdomen so that the poisonous glands at the end of the abdomen touched the upper jaw, and then licked its limbs repeatedly with the upper jaw (Figure 3). How to explain this seemingly strange behavior? Scientists have thought of a possibility: yellow mad ants use their own venom to eliminate the toxicity of imported red imported fire ants' venom.
In order to confirm this conjecture, the researchers designed a series of ingenious experiments. They painted nail polish on the venom glands at the end of the abdomen of some yellow mad ants, so that the yellow mad ants could not wash their bodies with their own secretions when attacked by the venom of the invading red imported fire ants, while the other part was only painted on both sides of the abdomen of the yellow mad ants. Next, they put two groups of yellow mad ants in contact with the invading red imported fire ants to observe their survival after being infected by the venom of the invading red imported fire ants. After 8 hours, 98% of the population of yellow mad ants whose abdominal ends were not blocked survived. On the contrary, only 48% of the yellow mad ants whose abdomen was blocked survived. Obviously, the liquid secreted by the abdominal gland of the yellow mad ant can effectively reduce the toxicity of the venom of imported red imported fire ant. In order to further confirm their conclusion, the researchers chose Argentine ants to do experiments. Argentine ants don't secrete "antidote" like yellow mad ants, so once they encounter the venom of the invading red imported fire ants, they will almost die. However, if the liquid secreted by the yellow mad ant is smeared on the Argentine ants infected with the invading red imported fire ant toxin, the survival rate of Argentine ants will be greatly improved. This further shows that the liquid secreted by the yellow mad ant is a good antidote to the venom of the invading red imported fire ant.
Seeing this, readers must be very curious. What magical chemicals are hidden in the antidote of yellow mad ants? The answer is simple, but it is only an organic substance-formic acid. In fact, many kinds of ants secrete formic acid for self-defense. It was first discovered that formic acid was obtained by distilling ants, so formic acid is also called formic acid. In order to confirm the detoxification effect of formic acid, the researchers conducted a series of experiments with Argentine ants. They found that the survival rate of Argentine ants attacked by imported red imported fire ants can be significantly improved if the venom secreted by yellow imported fire ants is replaced by formic acid aqueous solution, which irrefutably shows that formic acid is an effective ingredient in the "antidote" of yellow imported fire ants. So how does formic acid interact with the venom of imported red imported fire ants to reduce its toxicity? Unfortunately, at present, we are not very clear about its mechanism of action. Scientists speculate that formic acid may disable some enzymes in the venom of imported red imported fire ants, and it does not rule out that it can interact with various alkaloids, the main components of the venom of imported red imported fire ants.
Once the toxicity of the invading red imported fire ant venom is eliminated, the yellow mad ant will fight back with the same venom. Interestingly, the venom of the yellow mad ant does not contain special chemicals like the invading red imported fire ant. Its main components-formic acid and some alkanes-are also common in other ants. The combination of formic acid and alkane is really effective against the invading red imported fire ants, which can kill a large number of invading red imported fire ants. The researchers also noticed that although many other ants can secrete formic acid and alkanes, the secretion of yellow mad ants is much higher than other ants, so they speculated that winning by number is probably an important reason why yellow mad ants have an advantage in the competition with other ants. It's like two people holding pistols, one of which has only a few bullets, and I'm afraid I can only fire a warning shot in the face of danger; The other man has dozens of bullets on him, so he can safely shoot back.
Both the imported red imported fire ants and yellow mad ants originated in South America, and the two ants competed with each other, and the yellow mad ants obviously prevailed. This unique detoxification behavior of yellow mad ants may have evolved in the long-term competition history with the invading red imported fire ants, because researchers have found that if yellow mad ants are put together with other kinds of ants, yellow mad ants will not actively use their own venom to detoxify after being attacked by each other's venom. We were surprised that the yellow crazy ants could drive away the red alien fire ants that invaded the southern United States, but in fact, the couple may have staged countless similar stories.
For the residents in the southern United States, it is probably not a happy thing that the invading red imported fire ants are replaced by yellow mad ants, because yellow mad ants will also build nests everywhere to destroy facilities and attack other creatures like the invading red imported fire ants. It seems that although the "hooligans" have been driven away, they have been replaced by more powerful "bullies". In the near future, people there may continue to suffer from ecological problems caused by invasive species. However, for researchers and ordinary readers, the story of the invasion of red imported fire ants and yellow mad ants is a very good example, which makes us truly realize the magic of nature and the powerful power of evolution. [Author: Block * * * polymer (Doctor of Polymer Science and Engineering, now engaged in enterprise research and development)]