Top News · Henan Business Daily Reporter Wang Miaomiao
In summer, who doesn’t have an annoying “little buzz” around them?
Where does Henan rank in the country for the number of mosquitoes? For example, who are the mosquitoes that chase and chase us every day? For example, are there more or fewer mosquitoes around us? For example, mosquitoes have evolved for ten thousand years just to bite us? For example...
In order to turn each question mark into a period or an exclamation mark, a reporter from Top News · Henan Business Daily recently interviewed Zhao Qi, deputy chief technician of the Institute of Disinfection and Vector Control of the Henan Center for Disease Control and Prevention. From this, each mystery was solved.
Question 1: Where in China have the most mosquitoes? Where does Henan rank in the country?
"Mosquitoes like hot, humid and watery environments, so we can judge from this that there are the most mosquitoes in tropical rainforests." Zhao Qi said that the density of mosquitoes is also very high in watery grasslands, such as Beiwan, Habahe County, Xinjiang.
As one of the areas with the highest mosquito density in the world, Beiwan, Habahe County, Xinjiang, once set a record of 1,700 to 3,500 mosquitoes per cubic meter. This also requires the border guards there to be fully armed during the mosquito active season. mosquito.
According to the "2019 National Mosquito Monitoring Report", from June to September 2019, the mosquito density in residential areas in Inner Mongolia reached 22.6 mosquitoes per lamp per night, that is, each mosquito trap can catch 22.6 mosquitoes per night on average. , ascending to the position of having the highest number of mosquitoes in residential areas in the country. So, where does Henan rank in the country in terms of mosquito population?
"There is data on the number of mosquitoes in Henan, but our data is not 'how many mosquitoes are there in Henan', but what is the average density of mosquitoes in Henan Province." Zhao Qi said, according to the "2019 National Vector Mosquito Monitoring Report" According to the data, the average mosquito density in Henan Province is about 5 mosquitoes per lamp per night. Counting from high to low, Henan ranks around 20th in the country in terms of mosquito population.
In order to make it easier for everyone to understand how this data was obtained, Zhao Qi specially introduced their common method of mosquito monitoring, which is the mosquito trap method. This method uses the principle of light trapping to trap mosquitoes in residential areas, parks, hospitals, cowsheds, pig pens and other places. Because the trapping areas are all related to people’s living areas, they do not involve wild environments where mosquitoes are abundant.
Question 2: How many types of mosquitoes are there? What are the main ones in Henan?
"There are currently more than 3,500 known species of mosquitoes in the world." Zhao Qi's answer really surprised the top news·Henan Business Daily reporter.
I really don’t know that there are so many kinds of tiny mosquitoes.
Zhao Qi said that in Henan, mosquitoes that are closely related to people include Culex pipiens, Anopheles sinensis , Aedes albopictus , Culex tritaenorhynchus, etc. These mosquitoes all have some distinctive characteristics, making them easy to identify.
For example, Culex pipiens is the most common mosquito. It is the one that usually buzzes around people in the middle of the night. It is also the main vector of filariasis ; Anopheles sinensis is the main vector of malaria . In rural areas , especially common in places with ponds and paddy fields; Aedes albopictus can transmit dengue fever . It likes to breed in bottles, cans, discarded containers and other small stagnant water. It chases people and bites them from afternoon to evening. It is usually the most common mosquito; Culex tritaenorhynchus is the main vector of Japanese encephalitis and is found in rural areas, especially around pig pens and cowsheds.
Question 3: Has the number of mosquitoes in Henan changed in recent years?
"Through our continuous monitoring, the overall mosquito density in Henan Province has been fluctuating around '5 per lamp per night' since 2017, with no obvious fluctuations." Although the overall mosquito density in Henan Province has not seen obvious fluctuations in the past five years, There are still some differences in the seasonal changes in mosquito density in different years.
A typical example is July 2021. The mosquito density in that month was significantly higher than the same period in previous years. The main reason for this situation is actually the impact of the "7·20" flood, which caused more water bodies where mosquitoes breed and the density also increased accordingly.
Question 4: Are there mosquito monitoring points in Henan?
According to Zhao Qi, Zhengzhou, Luoyang, Anyang, and Luohe are "national vector bioecological monitoring points" that monitor the types, density, distribution, and distribution of four pests, including rats, mosquitoes, flies, and cockroaches. ecological indicators such as seasonal growth and decline, and regularly report monitoring data to the National Center for Disease Control and Prevention.
In addition, other provincial cities and Jiyuan Demonstration Zone are provincial-level monitoring points. They carry out vector biological monitoring in accordance with the national plan and report monitoring data to the provincial CDC . As for the method used by staff to monitor mosquitoes, the most widely used method is the "mosquito lure method", which uses mosquito lures of uniform specifications to hang in residential areas, parks, hospitals, cowsheds, pig pens and other places to trap mosquitoes, and then use them to trap mosquitoes. Return to the laboratory for classification, identification, and statistical analysis.
Question 5: Why do I always feel like there are mosquitoes around me?
To answer the above questions, we have to talk about the super reproductive ability of mosquitoes.
Generally speaking, mosquitoes can lay 50-500 eggs each time. These eggs usually hatch, grow, pupate, and emerge into adult mosquitoes in 1-2 weeks, and then take about 2-5 days. Over time, these mosquitoes can mate and lay eggs.
lays many eggs and iterates quickly, so the reproductive power of mosquitoes is really strong.
Question 6: Mosquitoes have evolved for ten thousand years to bite people?
"This statement is actually based on a study that said that a mosquito originated in Africa - Aedes aegypti , which bites both humans and animals, but spread to Aedes aegypti outside Africa and is still there. Aedes aegypti in Africa, although it still belongs to the same species, prefers to bite people. According to modern scientific research, this change is believed to have occurred about 10,000 years ago," Zhao Qi told a reporter from Top News·Henan Business Daily. , this study only shows that Aedes aegypti, one type of mosquito, had such changes 10,000 years ago, and cannot be generalized to all mosquitoes, and it is not appropriate to "romanticize" this event.
Question 7: Do mosquitoes choose to bite randomly, or based on smell and blood type?
Why do mosquitoes like you? Is it because you are sweet? Zhao Qi thinks this matter should be divided into two parts.
When choosing a mosquito to bite, you must first look at the "blood-sucking habits" of the mosquito itself.
Some mosquitoes prefer human blood, typical ones such as Aedes aegypti, Aedes albopictus, Anopheles anthropophila, etc.; some mosquitoes suck both human and livestock blood, such as Culex pipiens, Anopheles sinensis, and Anopheles tritaenioides. Mosquitoes, etc.; there are also mosquitoes that prefer to suck the blood of animals, but because these mosquitoes have little relationship with humans, the disease control department does not pay that much attention to them.
For a mosquito, which one it sucks is mainly related to the amount of carbon dioxide emitted by the human body, as well as the content of lactic acid, pyruvic acid , dimethyl disulfide and other substances in body surface sweat. Therefore, it is generally believed that people with strong metabolism and high carbon dioxide emissions, as well as people after exercise, are more likely to attract mosquitoes.
It should be noted that common infectious diseases such as malaria, dengue fever, and Japanese encephalitis are all related to mosquito bites. Therefore, prevention and treatment should be combined when necessary.
