“The Little Giant of the Advance” The strongest invading creature in history !? Argentine ant June 6, 15:24

A small creature, now feared to be the "strongest invader in history," is secretly breeding and expanding its range in Japan.

The name is "Argentine ant"

, a small ant native to South America, but it has become clear that it is invading our living area with explosive fertility.

Serious damage has been reported overseas to agriculture, ecosystems, and people's lives.

An invader who gives the biggest warning that researchers have "no waiting for countermeasures".

We approach the threat of the ecology and countermeasures.

(Naorou Shimada, Reporter, Faculty of Science and Culture / Close-up Gendai Interview Group)

Intercom that rings alone

Yuichi Kato and his wife, who live in Itami City, Hyogo Prefecture, were suffering from a strange phenomenon.

Yuichi Kato

"Ping-pong sounds all the time. When it comes out high, no one is there."

At first, I thought it was a "mischief of a child in my neighborhood."

The intercom that was just replaced.

It sounds so often, day and night, so I thought it was a malfunction.

There are countless ants and eggs clinging to it.

I was amazed at how it was moving.

Yuichi Kato

"I was surprised. It's really unpleasant. It seems that there was a phenomenon that ants touched the intercom equipment and made a sound. Now I bought a new one, and after that, the sound stopped. "

At Mr. Kato's house, there were other damages that seemed to be caused by ants.

Yuichi Kato

"It broke because it got in from the operation panel of the bath or the pipe. I had to change the electric water heater, and it cost about 800,000 yen in total. There are so many ants that it turns black, and my home is full of ants. "

Another woman, who lives in the same district, said she was suffering from sleep problems.

Woman

"I feel like I'm biting into the futon. I felt like I was there. Last year, I was quiet and I couldn't really sleep. I'm stressed. "Cha"

The strongest invading creature in history?

What is an Argentine ant?

It invades through any small gap, creates nests everywhere, and explosively increases the number.

The name of this ant that bothers the residents of Itami is the Argentine ant.

Yoshiaki Hashimoto, a specially appointed professor at the University of Hyogo, who is familiar with outpatient ants, warns as follows.

Yoshiaki Hashimoto, Specially Appointed Professor, University of Hyogo

"The great ability of this ant is to build a nest anywhere. On the contrary, it can spread anywhere. Also, the legs are fast and everyone moves to another place immediately. In addition, it lays 30 to 40 eggs a day and increases steadily. It is called "rat calculation", but it will increase exactly by "Argentina ant calculation". "

Argentine ants are exotic ants originally native to South America.

It is brown and is about 2.5 mm long.

I'm not sure how it came to Japan, but the idea that it was mixed in with the cargo carried by cargo ships from overseas is predominant.

In 1993, the invasion into Japan was confirmed for the first time in Hatsukaichi City, Hiroshima Prefecture, and the range of habitat has expanded to western Japan, the Chubu region, and the Kanto region.

It was designated as a specific alien organism in 2005, and as of June 2022, it has been confirmed in 12 prefectures according to the Ministry of the Environment and others.

Argentine ant threat 1 fertility

Compared to fire ants, which are the same specific alien species, Argentine ants have no poisonous needles, are smaller in body, and have weaker chewing ability.

Why are experts so vulnerable?

One of the reasons is "amazing fertility".

The source of its fertility is the "queen ant".

Common ants have one queen ant in their nest, but Argentine ants have many queen ants in one nest.

It breeds actively from spring to summer when the temperature rises.

According to experts, each queen ant lays 40 to 60 eggs a day, one of which is the new queen ant's egg.

So, simply put, a queen ant lays one new queen ant a day with the same spawning ability as herself.

Under good conditions, the new queen will become an adult and be able to lay eggs in about two months.

For this reason, the number of individuals will increase explosively, and with the overwhelming number as a weapon, other native species will be expelled.

A person in charge of a manufacturer developing an insecticide

"The breeding speed is too fast, and even if you remove a part of the nest, for example, it will be revived regardless. You can not get rid of it unless you kill the queen firmly."

Argentine ant threat 2 super colony

Another reason for the rapid expansion of habitat is the formation of huge kinship groups called "super colonies".

A group of the same blood relatives called "colony" that extends to a wider area is called a "super colony".

In the Mediterranean region, it is also known that a super colony extending 6000 km across the border from Italy to Portugal was formed.

In general, ants in different nests may contend with each other even if they are of the same species, but Argentine ants that are expanding overseas as foreign ants are related to each other with the same genotype and are like one huge family. By building a cooperative relationship by going back and forth between each other's nests and feeding, it is possible to further expand the power.

Forest Research and Management Organization Senior Researcher Eiki Sunamura

"Once a global super colony spreads, it can't be stopped. It's really awesome to cooperate and attack in a clique. be"

So much damage in the world!

New Zealand is one of the countries where huge super colonies have already been created and suffered great damage.

From spring to summer every year, the representative of the pest control company, who said that he was constantly consulted by the residents and was busy with the extermination work, confided a shocking case.

President of New Zealand Control Company Bib Van Dyke

"The most serious thing I've seen was damage at a facility for people with dementia. At night, ants on a patient sleeping in bed. Came in and licked the drool on his face, in his ears, nose, eyes and mouth. In terrible situations, the nursing staff spent the night wiping ants off the patient. I did. "

Argentine ants have also been reported to prefer to collect in patient blood and body fluids such as pus.

It has also been pointed out that ants with pathogens attached to the surface of the body may spread the infection in hospitals.

Serious damage has also extended to industry.

Pete Johnston, a beekeeper in the northern suburbs of Auckland, New Zealand, has been unable to beekeeping where he used to be due to the outbreak of Argentine ants.

Beekeeper Pete Johnston

"I was really disappointed. The ants broke into the beehive and ruined it. The honey was eaten up and the bees were killed. Stop them. Is impossible "

In Oakland, in order to carry out pest control work efficiently, we are raising detection dogs that can detect Argentine ants that are difficult to see by smell.

Auckland City Biosecurity Advisor Brian Shields

"If you don't do anything, Argentine ants will spread all over New Zealand."

As for the impact on agriculture, major damage has been reported in citrus fruits such as oranges and vineyards in the United States, South America, and South Africa.

Argentine ants have the property of protecting insects that harm plants such as aphids and scale insects from natural enemies, and the plants are secondarily damaged.

The actual situation of ant damage in Japan is also revealed for the first time

In April, mass breeding of Argentine ants was revealed on a part of the site of Osaka Airport in Itami City, Hyogo Prefecture, where Mr. Kato and his colleagues introduced at the beginning live.

Experts point out that Argentine ants have a habit of gathering in electronic devices and cables, which can cause short-circuits and abnormalities in airport equipment.

At the same time, there was concern that the habitat was expanding to residential areas around the airport, and Hyogo Prefecture launched a countermeasures meeting.

When I conducted an interview in a residential area around the airport with Mr. Hashimoto, who is the chairman of the conference, it became clear that the damage had been going on for at least three years.

Hashimoto et al. Conducted a questionnaire to local residents in early May.

As a result, the actual situation of serious damage caused by ants has become clear.

Answers were obtained from 133 households.

Approximately 80% (78.19%) of them answered that they live in large numbers and suffer damage and stress.

And about 20% of the houses that were damaged by the invasion answered that they had "sleep disorders" due to ants getting into the futon and biting their legs or putting their arms on them.

In the year when we started to feel that there were many ants, the number of households in 2018 increased from 9 to 22 in 2019.

After that, in 2020 and 2021, there were 28 households.

Regarding the details of the damage (multiple answers available)

, "Invasion into the house (89 households)"

, "Flocking to food and equipment (71 households)"

, and "Invasion into outdoor storage / potted plants (68 households)" ranked in the top three. Occupied.

In addition,

"dysfunction due to equipment damage, ant death, and dirt such as dung (6 households)" was also observed.

In the case of outdoor intrusion, responses such as "intercom", "security camera", and "air conditioner outdoor unit" were received.

Voices of residents complaining about the damage that was revealed for the first time.

Mr. Hashimoto has issued the largest warning that immediate measures are needed.

Yoshiaki Hashimoto, Specially Appointed Professor, University of Hyogo

"We are on the verge of winning or losing to ants. If we don't start taking measures right away, terrible hell awaits us."

Defend the "defense line" from the small advancing giant

On this day, Mr. Hashimoto headed for the collection of an adhesive sheet called a "trap" that had been set up along the national highway in advance.

By examining the number of Argentine ants caught in the trap and determining the exact range, it is possible to plan effective control.

Observe the ants in the trap one by one using a microscope.

It's a daunting, steady task.

The countermeasure team has mapped the survey results of more than 200 points so far.

I was able to identify the approximate distribution area.

Inhabitation was confirmed in an area of ​​250,000 square meters on the west side of the airport, but it did not extend to the dense urban area beyond the arterial road on the south side.

For this reason, we decided to set the national highway of the arterial road as a defense line and protect it.

Yoshiaki Hashimoto, Specially Appointed Professor, University of Hyogo

"Once Argentine ants settle in a residential area and breed. For example, we are living in ant nests. It's stopping the "small march giant". It's important not to break through this wall. "

"Private land" wall to eradicate ants

What is important for effective control and curbing the expansion of habitat?

Toyohashi City, Aichi Prefecture, continues to fight against Argentine ants even now, more than 10 years after its first discovery.

Argentine ants were first found in Toyohashi 11 years ago.

It was a part of the factory complex near the port of Akemicho.

I immediately worked on the extermination work, but a big wall stood up.

Private private lands, such as factories, could not enter the investigation or force them to control it.

The city's control and surveys were limited to areas such as along roads, and it took time to grasp the distribution area.

Mr. Ken Yamazaki, Environmental Conservation Division, Toyohashi City

"There was a problem that we could not enter the land of the company. If it breeds on the land of the company, it is very difficult to exterminate it, and it increases without knowing it. And sometimes it moves steadily, so I can't identify that amount. "

And six years after the first discovery.

The outbreak was also confirmed in a residential area in the center of the city, about 10 kilometers northeast.

The city has nearly quadrupled the cost of countermeasures, but it has not kept pace with the increase and is still in a state of retreat.

Mr. Ken Yamazaki, Environmental Conservation Division, Toyohashi City

"It's a very painful place, but the habitat is expanding. I'm doing my best, but the level of expansion is too fast to catch up with some parts."

Under these circumstances, we are starting to make new efforts to improve the effect as much as possible.

By adding sweetness with "jam" to the commercially available extermination bait, it is made easier to bite.

Kei Shuto, who was in charge of developing a new extermination bait at that time, said,

"I put about one-third of the jam in the commercially available poison bait. I'm trying to make it a blueberry flavor and a strawberry flavor next month, so I'm giving variations to the taste so that ants won't get bored. "

When I actually used it in the field, ants swarmed around the jam.

Certainly the bite looks good.

Two years have passed since the development of the bait.

The search for eradication continues even now.

Kei Shuto, who was in charge of developing new bait for extermination at that time,

"I want to win the battle with ants, but it is difficult. There are many, and I have managed to stop it so as not to increase it any more. is"

Get a quick understanding and succeed in eradication

On the other hand, there are some areas where the Argentine ants that once spread have been successfully eradicated.

It's Shizuoka city.

Mr. Toshiro Kishimoto of the Fujinokuni Museum of Natural and Environmental History, who has been involved as an advisor to the city.

The deciding factor for his success was "community cooperation."

About one year after the ants were first found, they were confirmed to live in the area of ​​about three Tokyo Domes.

This range included not only houses but also factories and commercial facilities, but with the cooperation of the owners of almost all the sites, it was possible to grasp the actual situation.

Fujinokuni Museum of Natural and Environmental History Kishimoto Toshiro

"There were various landowners such as companies and private houses in this area, but the administration side also explained carefully, so we will get the cooperation of the local people. This was a big deal. "

Shizuoka City repeatedly held briefing sessions for residents and politely appealed for the need for countermeasures.

We also distributed more than 200 copies of the "circulation board" with the extermination bait as an appendix.

Mr. Ryoji Ikuma, the person in charge at that time in Shizuoka City

"There was no direct damage to the residents at that time, so there were voices asking why I would do it, but I have to do it now. I explained that I shouldn't do it. I think I was able to share with everyone the sense of crisis that I had to move quickly. "

By controlling all areas of the habitat found in the survey, Argentine ants were rarely seen in the third year, and eradication could be declared in 2019.

Even now, we continue to monitor with experts for signs of re-invasion or outbreaks.

And recently, with the disappearance of Argentine ants, nostalgic creatures that once disappeared have also appeared.

Fujinokuni Museum of Natural and Environmental History Kishimoto Toshiro

"It's a native ant, and it's a kind of Umematsuo ant. When Argentine ants were around here, there were almost no native ants, so what are the native ants? I'm deeply moved to walk the kind. "

Regarding the entry of private land, which has been a barrier to surveys and control, the Alien Species Act will be amended so that prefectures and municipalities will be able to enter for the purpose of habitat surveys from next spring.

The first step is to be aware of familiar "incidents"

Argentine ants that may live close to us.

What should I do if I see a suspicious ant?

Argentine ants have some characteristics, but it is difficult for amateurs to distinguish them.

Be careful if you are lining up in a strip or if the speed of movement is faster than other ants.

Control is possible with commercially available poison baits (bait agents) and insecticide sprays, but there are also cases where a large amount of them invade houses.

The Ministry of the Environment recommends that if you find one, you should not catch it carelessly and consult with the manager or government agency of the place.

The National Institute for Environmental Studies has released a database that describes the characteristics and distribution areas of invasive species on its website, and I would like you to refer to it.

"It is important to be aware of the incident," said Koichi Goka, director of the National Institute for Environmental Studies.

Koichi Goka, Director of the National Institute for Environmental Studies

"What kind of creatures are usually around the familiar life we ​​live in? By knowing, we can notice" abnormalities ". First, we need to know the surrounding nature. , That is the first step we can take to combat alien species. "

What alien species ask

Argentine ants are said to live quietly on the leftover food of other creatures without expanding their power to this extent because they have natural enemies in their place of origin as well as competitors such as stronger ants.

However, once they went abroad, they suddenly became invading creatures, also known as the "strongest in history."

Surrounded by the sea, Japan has no natural enemies or competitors for alien species, and is blessed with hidden places such as vacant houses and abundant food, making it a truly heavenly environment.

It must be remembered that it is not only their unique ecology that they are expanding their power to this extent, but in fact, it is also partly on the part of us human beings.

Naorou Shimada

,

Reporter, Department of Science and Culture Joined

Fukuoka Prefecture in 2010

After working at Hiroshima-Shizuoka-Fukuoka Bureau, he is currently

in charge of cyber security and consumer issues in the IT / Culture Group.

I started

Close-up Gendai broadcast on June 6th!

Battle with the quiet invader "the strongest in history" Argentine ants