"I was bitten by a red fire ant once, and that night (the sting site) was red, swollen and hot, and the bulging bag was the size of a palm, as if another knee had grown on the leg...... At the worst time, the scalp is numb, and the whole person is dizzy. Ms. Xia described to Jiupai News how she felt after being stung by red fire ants.
Red fire ants, native to South America, have a reddish-brown color and a similar appearance to common ants, about 3 mm to 6 mm long. It has been described as "recognized as one of the 100 most dangerous invasive species in the world" and has been listed as a national agricultural, forestry and phytosanitary pest.
Since the first invasion of Taiwan in 2003 and the discovery of red fire ants in Wuchuan, Guangdong Province the following year, red fire ants have spread rapidly in the mainland. According to the survey of the National Agricultural Plant Epidemic Monitoring Network, in 2023, 6.23 million mu of red fire ants have occurred in 642 counties in 12 provinces in the southern part of the mainland, including Zhejiang, Fujian, Guangdong, Guangxi, and Hainan. Experts believe that red fire ants have been colonized in the mainland for nearly 20 years, with a large area base, and the risk of diffusion with seedlings and lawns is high, and the situation of quarantine supervision and interception prevention and control is still relatively grim.
Dong Likun, a senior engineer at the Institute of Plant Protection of the Wuhan Academy of Landscape Sciences, said that red fire ants can threaten the health and even life safety of humans and animals. Red fire ants are very prone to high-density colonies in newly invaded areas, and once a person or livestock steps on an anthill, they will dump out of their nests and crawl on their bodies in swarms to bite.
He reminded the public that if they find a nest of red fire ants around their homes, try to bypass and avoid approaching the nest, and suggested that they should immediately report to the garden and forestry department, and the relevant technical departments or professional control agencies and companies should carry out the prevention. If you are accidentally stung by red fire ants, you should wash the wound with soap and water before going to the hospital in time.
[1] Red fire ants: one of the 100 most dangerous invasive species recognized in the world
Dong Likun introduced to Jiupai News that the biggest feature of red fire ants is that they often appear in grass, farmland, wasteland, roadsides, parks and other places, and the fine particles of soil chips dug up from the ground are piled into mound-like ant nests, which are honeycomb-shaped inside, while the nests of ordinary ants will not bulge; If you peel off the surface, there will be many dark red ants gushing out, large and small, among which the large is a soldier ant, and the small one is a worker ant, all of which can bite and sting.
Morphology of the red fire ant queen under a microscope. Photo/Xinhua News Agency
"Different from ordinary ants and bees, red fire ants are not obvious in their nests, and new queens will be produced after the marriage and breeding period between the queen ant and the male ants, and they will fly everywhere and spread to establish new nests, and later these new nests will be connected with the original nest in a network, and the internal connections will form a 'super nest' full of anthills in an area of one or two hundred square meters, and continue to spread around." This is also the problem that red fire ants are difficult to control, he said, because their reproductive ability is too strong. There is more than one queen in a nest, and the removal of one nest will bring the other nest back, and it cannot really cut off the reproductive ability of the nest and destroy the entire nest.
What exactly are the dangers of red fire ants? Qi Guojun, director of the Agricultural Biosecurity Research Office at the Institute of Plant Protection of the Guangdong Academy of Agricultural Sciences, has pointed out that red fire ants can affect agricultural and forestry production, destroy public facilities such as electricity, transportation and communications, and in the long run, it will also destroy the ecological balance, attack terrestrial insects, birds and small mammals, and cause biodiversity decline.
Dong Likun explained that red fire ants mainly feed on the seeds, young shoots, young stems, and fruits of crops, which directly affect agricultural production; It will also eat some small insects in its distribution; It will also compete with ant species on a local scale and grab food, causing a trend of squeezing and destroying biodiversity.
"The invasion of lawns and green spaces in southern China has led to a decline of more than 80% in the local ant population due to the invasion of red fire ants; In the United States, local ant populations also declined by more than 70 percent in areas with severe red fire ant infestation, and arthropod species richness also decreased by 60 percent. Zhang Lei, a researcher at the Institute of Plant Protection of the Chinese Academy of Agricultural Sciences, said.
[2] Sensitive people are bitten by red fire ants or go into shock
Dong Likun told Jiupai News that in addition to the above hazards, red fire ants can also threaten the health and even life safety of humans and animals.
Red fire ants are very prone to forming high-density populations in newly invaded areas, and once a person or livestock steps on an anthill, they will pour out of their nests and crawl on their bodies in groups to bite, "Other ants may run away when they bite, but red fire ants are very aggressive, they will not let go when they sting, they will bite the skin with their upper jaw forceps, and then pierce the tail needle and continue to release venom." "This increases the probability of disease in livestock and poultry, affecting their normal growth.
According to the Beijing Center for Disease Control and Prevention, after the human body is stung by red fire ants, the injured area will have continuous burning pain, local skin formation of erythema, blisters, hard swelling, itching, and blister bursting, which often causes bacterial secondary infection.
In addition, about 2% of people have an allergic reaction to the protein in the venom released by red fire ants, and sensitive people will have symptoms such as flushing, hives, and even difficulty breathing, and severe allergic reactions will have symptoms such as vomiting, dizziness and shock, which may be life-threatening if not treated in time.
Ms. Xia is a northerner, recently came to live in the south, once she wore slippers in the community for a walk, the community is rich in greenery, but was accidentally stung by red fire ants on the right leg, and then went out several times, even if she wore socks and trousers, she was still bitten on her left leg, ankle and the back of her hand one after another.
Marks left after being stung by red fire ants. Photo / provided by the interviewee
"Maybe it's because of my physique, I was the only one around me who was bitten, and the night of the bite (the sting site) was red, swollen and hot, and the bulging bag was the size of a palm, as if there was another knee on the leg, and it would itch my heart during it, and I couldn't sleep at all. After about two days, the swelling subsided, and the yellow blisters bulged again, and after scratching, it will become a scar with a hole in the middle, in this case, it is not only itchy but also painful, the pain is the kind of swelling, stinging and scratching pain, and then the process of blood scabs and scratching is repeated during that time. At the worst time, the scalp is numb and the whole person is dizzy. It's been a month and a half now, and it's not completely well, and the bite area still itches when I sleep at night. She described to Nine News how she felt after being stung by red fire ants.
Ms. Xia also said that especially the itching at the sting site, she would use a hair dryer to blow hot air to relieve it, but the effect was very short-lived, and she could only boil hard in the end. "Being bitten by a red fire ant once is 'fatal', not to mention that I have been bitten several times in a row, and now I still have marks everywhere on my body."
Ms. Wu, a resident of Guangdong who had a similar experience to Ms. Xia, said that she was unfortunately bitten by red fire ants under a tree, and at first she didn't think it was a big deal, but the wound began to itch, hot, red and swollen that night, and the redness and swelling continued to spread in the next few days, and the pain was obvious, and she couldn't sleep all night.
Wounds after being stung by red fire ants. Photo / provided by the interviewee
"I thought I had been poisoned, and the bite on my leg was horrible, and the pain was so unbearable that I even wondered if I would have to amputate my leg. Later, the dermatologist said that it was insect bite dermatitis, and prescribed two mometasone furoate creams, which were applied 3 times a day and continued to be ice, and after 3 days of medication, they finally slowly recovered. She said that red fire ants are very common in Guangdong, and now they must have anti-mosquito medicine when they go out, and they dare not stand under trees and grass unless they have sprayed beforehand.
Mr. Wu, a resident of Guangxi, also said that there are many red fire ants in southern China, especially near the grass, and signs have been erected in the park to remind them, but the number is too large to be eliminated almost completely, so he can only take precautions and try to stay away from the mound-like ant nests.
[3] The professional prevention and control measures of red fire ants have been relatively mature, and the relevant work has achieved initial results
In addition to farmland, woodland, lawns, green spaces and watersides, open-air power equipment boxes, airport runway indicator lights, air conditioning outdoor units, etc. are all places where red fire ants like to nest and gather in large numbers, which can easily cause short circuits or failures in power facilities, seriously affecting the safety of public facilities.
So, how to prevent red fire ants? Are there effective measures? Where are the key points of prevention and control?
Dong Likun introduced to Jiupai News that the key to the prevention and control of red fire ants is to grasp the early stage, when the red fire ants have just invaded and the amount is small, it is necessary to pay close attention to prevention and control, and timely uprooting, once it spreads in large quantities, especially in sparsely populated and thorny mountains and forests, it is difficult to prevent and control.
He pointed out that the professional technical prevention and control measures for red fire ants have been relatively mature, and a variety of measures are generally adopted for comprehensive control. Since the queen ant and most of the worker ants are inside the nest, and the nests of the red fire ants are connected, if only the agent is poured on the surface, it cannot be eradicated, and the whole area needs to be controlled.
At present, the more effective control strategy is to spray pesticides on the periphery of red fire ant nests and ant mounds to kill part of the red fire ants on the surface, control them, and prevent further spread, and then feed poisonous bait or nest irrigation to the inside to reduce the overall population number, and at the same time control the tendency of their spread to the periphery by spraying pesticides during their breeding and marriage flight period.
Nest morphology of red fire ants in the wild. Photo/Xinhua News Agency
"The measure of feeding poisonous bait is booby-trapping, red fire ants like to eat animal protein and starchy substances, we often use ham sausage as bait, doped with indoxacarb, fluoroethylene, dinotefurin and other biological insecticides, this agent has low toxicity, will not poison them at once, wait for them to feed each other and bring food back to the nest, the whole nest of red fire ants including the queen ant queen to take the poison bait, the whole nest will be quickly destroyed." Dong Likun explained.
Jiupai News noted that in March 2021, nine departments, including the Ministry of Agriculture and Rural Affairs, the Ministry of Housing and Urban-Rural Development, the Ministry of Transport, and the National Forestry and Grassland Administration, jointly issued the "Notice on Strengthening the Prevention and Control of Red Fire Ants" (hereinafter referred to as the "Notice"), and held the "National Red Fire Ant Joint Prevention and Control Action Launching Ceremony" in Zengcheng District, Guangzhou.
The "Notice" pointed out that the Ministry of Agriculture and Rural Affairs, together with the Ministry of Housing and Urban-Rural Development and other eight departments, has established an inter-ministerial working mechanism for collaborative prevention and control of red fire ants, and organized and coordinated the interception and prevention of red fire ants.
The agricultural and rural departments are responsible for organizing the monitoring, prevention and control of agricultural production plots, rural living areas and surrounding areas; The forestry and grassland department is responsible for organizing the monitoring, prevention and control of woodlands, grasslands, nurseries and other areas; Each customs directly under the customs is responsible for organizing the monitoring of the port of entry, the storage area of imported goods and containers, and notifying the port operation and management department to carry out prevention and control; The departments of housing and urban-rural construction, transportation, water conservancy, and railways shall cooperate in the monitoring, prevention and control of areas prone to red fire ants, such as urban parks, green spaces and landscaping belts, water conservancy projects, and green areas around rivers, lakes and reservoirs, green belts within the land use range on both sides of highway traffic lines, and green belts within the boundaries on both sides of railway lines. The postal administration organizes the inspection of the plant quarantine certificate of the county (city, district) where the epidemic occurs to receive and send relevant mail and express mail; The health department is responsible for guiding medical establishments to standardize the work of medical treatment.
The Ministry of Agriculture and Rural Affairs has also formulated and issued the Emergency Plan for the Prevention and Control of Red Fire Ants, the Monitoring Regulations for the Epidemic of Red Fire Ants, and the Technical Regulations for the Chemical Prevention and Control of Red Fire Ants, and has set up 933 special epidemic monitoring stations in key areas across the country to organize agricultural departments at all levels to prevent and control the epidemic.
In addition, at the 2023 National Red Fire Ant Prevention and Control On-site Meeting held by the Department of Planting Industry Management of the Ministry of Agriculture and Rural Affairs and the National Agricultural Technology Extension Service Center in Yunxiao County, Fujian Province, relevant departments pointed out that through the efforts of agricultural and rural departments at all levels in the mainland, with the support of the central government's prevention and control subsidy funds, and through the vigorous promotion of joint prevention and control and unified prevention and control by agricultural and rural departments at all levels in the mainland, the interception and prevention and control of red fire ants have achieved initial results.
First, the spread of the virus has slowed down. After continuous interception and prevention and control, there has been no increase in new provinces since 2021, and the number of new counties in the epidemic has also decreased significantly.
The second is the reduction of the area of occurrence. In 2022, the occurrence area of red fire ants in China will decrease by 100,000 mu, which is the first time in the past ten years that there will be a decline inflection point.
Third, the degree of occurrence has been reduced. At present, the average live ant nest density per mu is less than 5, and the reoccurrence area of ant nest density greater than 30 accounts for only 0.3%, a decrease of 74 percentage points from the historical peak.
Dong Likun also said that Hubei Province first found red fire ants in Caidian District, Wuhan City in 2018, and then successively discovered several red fire ant distribution points, after active and timely prevention and control, some ant nests that spread in the later period have been basically controlled and removed.
He reminded that at present, red fire ants have entered the active period, if the public finds that there are red fire ant nests around their homes, try to bypass and avoid approaching the ant nest, and it is recommended to report to the garden and forestry department immediately, and the relevant technical departments or professional control agencies and companies will carry out prevention. If you are accidentally stung by red fire ants, you should wash the wound with soap and water before going to the hospital in time.