I saw a video some time ago. A young man said that when he was playing in the mountains, he saw a ball of thread similar to an iron wire ball in the creek. He thought it was very strange. There were sparsely populated areas here, so how could there be an iron wire ball? So I used a stick to pick it out of the water and put it on a stone. After a while, I found that this thing could still move.
I poked it again with a stick, but it didn't come apart, so I took out my phone and took a video.
After taking the photo, the young man put the "thing" that looked like a creature back into the water.
After the video was released, netizens accused the young man of actually putting the thing back into the water, and even asked him sharply:"Don't you know this is a parasite? A parasite that manipulates its host!"
Are wire balls parasites? Is it the reason why the mantis commits suicide by drowning in the river?
In fact, this moving "iron wire ball" is actually the well-known iron worm.
Its shape is similar to spaghetti, linear, with a diameter of about 1-3 mm, and the largest length can reach 2m.
This bug is dioecious, and when mating, multiple wireworms will intertwine to form a tight "breeding ball." From the appearance, it looks like a ball of string.
Ironworm is a parasite that can move freely after adulthood, but before adulthood, it will parasitize in other animals and survive by sucking nutrients from the host.
Its most famous host is the praying mantis, and locusts are also one of them. There are many kinds of ironworms, most of which live in fresh water, and some like to live in sea water, so lobsters are also one of their parasitic targets.
As a parasite, the strangest thing about ironworms is thatIt can control its host and actively jump into the water.
As we all know, terrestrial insects like mantises will not take the initiative to approach water sources. They usually absorb water from rain and dew. Jumping into the water is equivalent to committing suicide.
However, after being infected with iron worms, the mantis will actively look for water sources and actively throw itself into the river at specific times. At this time, the parasitic iron worms in the body will emerge from its tail.
This scene is very uncomfortable. Even though the mantis is small, it can have more than a dozen fat and long iron worms emerging from its body.
In order to utilize the limited space of the mantis as much as possible, the iron worms will wrap and fold with each other. It is said that an ordinary praying mantis can fit 36 iron worms in its body. It is truly a master of space utilization.
Parasitizing the body of a mantis, there is no need to find food on its own. Why did the iron worm eventually give up such a privileged life?
From a scientific perspective, this is because it needs to reproduce the next generation.
Ironworms go through three stages in their life: eggs, larvae and adults.
The adult insects are dioecious, just like the "thread ball" mentioned at the beginning. They will meet in the water and reproduce to produce the next generation. These eggs will be eaten by some aquatic insects, and then these small insects will be eaten by terrestrial insects such as mantises. Finally, these larvae will remain in the mantises.
After the mantis is parasitized, there will be no major changes at first. As the larvae grow older, the mantis's foraging activities will become more and more frequent, but the mantis itself will become thinner and thinner.
When almost all nutrients have been robbed by the iron worms, the mantis is already weak, but the iron worms have matured and they urgently need to come out of the body to complete the important event in life - mating.
Driven by the iron worms, the mantis slowly walks into the water, and the worms emerge from the body. With luck, the mantis can still survive, but it may still become a parasite.
Steal host genes to control the host
Scientists have been exploring why mantises throw themselves into rivers, and how do iron nematodes control mantises?
Scientists have proposed various hypotheses on this issue.
Some people believe that after being parasitized, the mantis is extremely deprived of nutrients and will be very thirsty, so it rushes into the water source;
Some studies show that praying mantises are attracted to polarized light;
Some scientists also said that it is because the iron worms secrete some special proteins to control the behavior of the mantis, forcing it to actively approach the water source.
But if the reasons are analyzed from a genetic level, then the latest research shows that the iron worms try to seize the host's genes to control the host's behavior.
According to reports, Tappei Mishina, a biologist at Kyoto University in Japan, and his research team conducted a genetic analysis of iron worms and selected three periods, that is, before, during and after control, and then compared them.
turn out,After Ironworm takes control of the host, its gene expression changes at the genetic level, with about 4,500 genes. There are 1,400 genes among them, which are very consistent with the genes in the mantis.
Most importantly, these 1,400 genes were not found at all in the iron worms that did not control the mantises.
To put it more simply,When the iron worm was inside the mantis, it stole the mantis's genes. As a result, the iron worm had many genes similar to those of the mantis, and these genes created some substances. These substances are the key to controlling the mantis.
The behavior of iron worms stealing genes from mantises is called "horizontal gene transfer". This is relatively common in some bacteria, but it is relatively rare to occur between two unrelated organisms.
This is equivalent to taking someone else's genetic code, which is quite scary when you think about it.
Is the movie "Invasion of the Ironworms" real?
In 2012, a very scary movie was released in South Korea called "Invasion of the Iron Worms". The scene was very scary.
Ironworms are widely distributed in our country and are found in Yunnan, Sichuan, Guangdong and Guangxi, Chongqing and other places. This means that we actually have many opportunities to come into contact with ironworms, especially those tiny eggs that are not easily found when mixed in water sources.
Will iron worms invade the human body? Will the scenes in the movie appear in reality?
first,To be clear, iron worms can parasitize the human body. Although the human body is not the main host choice, it will.
If you eat undercooked food or unclean water, you may become parasitic.
According to statistics,In most cases of parasitism, the site of parasitism is also in the digestive tract. The parasitized people are generally sallow and thin, appear malnourished, and are accompanied by digestive tract diseases.
However, human body infection with ironworms cannot be controlled. On the contrary, the symptoms will be much milder than those of praying mantises. Generally, the parasites can be expelled from the body by taking anthelmintics. Even if the parasites are in special places, such as the urethra and eyes, there have been no deaths.
There are not many cases that can be checked around the world. About 14 countries have reported similar cases of human infection.
This shows that the human body still has a certain immunity to this parasite, so there is no need to worry too much about iron worms parasitizing the human body. You can avoid it by not eating raw food and drinking raw water.