Entomologist pointed out Japanese research shows insecticide-resistant mosquitoes in Vietnam and Cambodia do not affect Thailand, revealing why mosquitoes mutate into “super-mosquitoes” and suggesting 11 ways to prevent insecticide-resistant mosquitoes.
The whoosh…whew…of “mosquitoes” can always be annoying. Many people want to get rid of this distraction, both slapping and injecting, because if bitten, there will be wounds and itching all day. Not only that, “mosquitoes”, small insects, are also carriers of serious diseases to people.
The severity varies according to the species of mosquitoes such as the Aedes aegypti and the garden mosquito. Is a carrier of dengue fever, mosquitoes bother the rice fields is a carrier of encephalitis, anopheles is a carrier of malaria, tiger mosquitoes and Aedes aegypti is a carrier of elephantiasis Therefore, be careful not to get bitten by mosquitoes.
While recently, Japanese researchers Study samples of “mosquitoes” in many countries, especially Vietnam and Cambodia where outbreaks of “Dengue fever” by the mutation of Aedes aegypti mosquitoes. “super mosquito” (super mosquito) that is resistant to insecticides Especially the chemicals in the “Pyrethroid” group, mosquito sprays that are commonly used in home injections.
Then such a discovery in neighboring countries in the same region as Thailand Causing you to prepare to cope or defend, how does Thailand already have “mosquitoes” that are stubborn?
Thai PBS online chat with Dr. Piti Mongkollangkun, Entomologist, Insect-Borne Disease Division, Department of Disease Control Answer questions regarding “mosquitoes” resistant to chemical insecticides To understand “mosquitoes” more, can eliminating “mosquitoes” be done the same way or not? And what to do if “mosquitoes” are harder to kill? Including the correct way to prevent
Why did mosquitoes mutate into “super mosquitoes”?
Dr. Piti said that the use of chemicals to prevent and control the bad “mosquitoes” is still necessary. To stop the spread of various infectious diseases, some mosquito vectors who are infected during the spread of disease must be killed as quickly as possible by using insecticide spray
In order to break the cycle of the outbreak, preventing the spread of infected mosquitoes to bite and spread the disease to others Importantly, to control the disease, we must also destroy the larvae’s breeding grounds.
mosquito insecticide resistance Insecticide resistance (insecticide resistance) is defined as the development of the ability of a particular mosquito species to withstand a normal dose of an insecticide that would be lethal to a normal population of mosquitoes of the same species.
Insecticide resistance is directly related to mosquito genetics. This is the result of a change in the genetic composition of mosquitoes that are selected to survive following being sprayed with insecticides. In which the majority of the weak population will be killed normally, but the healthy population will have a chance to survive and produce offspring.
The surviving mosquito population continues to increase its resistance to insecticides in its genotype until a large change in what is known as the “Mosquitoes are resistant to insecticides”. Resistance to insecticides often arises from “mosquitoes” frequently being exposed to insecticides from squandering mosquito spraying. or inefficient spraying, not technically correct
Today’s mosquitoes sprayed with insecticides may not die. The current medicine can only repel mosquitoes. only from one point to another one that can escape Will produce offspring that are more resistant to insecticides, known as survival, adaptation, tolerant traits, durability
Dr. Piti further explained that Mosquitoes that survived the injection of pesticides Will adapt until a special “gene” may be born to control the mosquito’s body to produce more detoxification enzymes. Therefore, when sprayed with the same type of substance, mosquitoes will not die. At that stage, it can be called “Mosquitoes are already resistant to insecticides.
Not only do mosquitoes develop resistance to chemical insecticides when they are frequently exposed to them. But mosquitoes are also able to resist their own death when insecticides are applied through behavioral changes. by the World Health Organization Classify resistance to insecticides into 3 types:
1. Biochemical resistance: In this mode, insecticides are degraded or reduced toxicity by at least one detoxifying enzyme before the chemicals reach their active sites in the mosquito’s body.
2. Physiological resistance Physiological resistance is any resistance to reducing the toxicity of insecticides through changes in the basic physiology of mosquito bodies.
In this form, the chemicals are not degraded. to be in a less toxic form Instead, mosquitoes resist the chemical by altering one or more of their physiological functions, such as reducing the sensitivity of neurons to pyrethroid insecticides. Causing mosquitoes to stun less or not stun at all (knockdown resistance)
When exposed to the substance and may fly away. Before full exposure to the toxin, enzymes are converted. Acetylcholinesterase to be less susceptible to being inhibited by organophosphate insecticides and the carbamate group
increase the thickness of the body wall to reduce the penetration of insecticides into Harm the body, increase the excretion of toxins from the body, or retain toxins in body fat so that they do not work, etc.
3. Behavioral resistance involves changes in mosquito behavior. to avoid exposure to insecticides Causing those mosquitoes to survive without exposure to chemicals or may be hit in small amounts, only the vapor of the substance
Insecticide-resistant mosquitoes in Vietnam and Cambodia do not affect Thailand.
Dr. Piti said Aedes mosquitoes are mosquitoes that do not fly far. especially mosquitoes It is a mosquito that likes to feed on human blood. Will like to live in people’s houses, can fly 100 meters a day, or rarely fly at all
One day, just fly off the wall where mosquitoes rest. from the closet or flying from the bathroom to bite someone who lives in the same house and then flew back to the original island One day may fly less than 10 meters.
Therefore, if staying in a favorite house with prey that likes to eat blood in the house is already good, then there is no need to fly out of the house far away.
Therefore, the opportunity to bring pesticide resistance genes to spread elsewhere. Or spread across the border to other countries is almost impossible.
Insecticide resistance is usually for Aedes aegypti, which is a mosquito that doesn’t fly far. We are often found to show stubbornness in patches. does not cover a vast area Aedes aegypti is often only resistant to pesticides at the village level.
The cause of stubbornness is some people or organizations with duties related to the control of diseases or insects that carry diseases Wasteful use of insecticides without taking into account the disadvantages of using these toxins at all
A fuss, when he saw a lot of mosquitoes, he constantly asked the staff to come and spray them. By not helping yourself or choosing any other mosquito control method at all.
Just because mosquitoes are resistant to pesticides in this village does not mean that every village in this district or villages far away will also have resistant mosquitoes as well.
global warming factor “Mosquitoes multiply – grow faster – breed faster and get hungry more often.”
Dr. Piti said that global warming causes mosquito breeding water to be warmer by less than 1 degree Celsius, which affects the larvae. That grows in the water is to cause the metabolism in the body of the larvae to occur faster. causing various systems within the body to change rapidly
Therefore, the larva will change the distance very quickly. In which mosquitoes change shape in 4 stages, namely the egg stage, the larvae stage, the robber stage and the adult stage. The adult female stage is the stage that feeds on blood. for the development of mosquito eggs As a result, the transmission of contagious diseases by mosquitoes serves as a carrier of disease from one person to another.
Pest range of Aedes aegypti mosquitoes Normally it takes 2-3 days to build the beak, wings, legs and change the body. Global warming causes this period to be shortened to only 1-2 days, on average it takes regarding 1 and a half days to be able to molt into a mosquito.
But the mosquitoes that occur are smaller than normal. Because of the small larvae When born as a mosquito, it’s a small mosquito. When the distances are shorter, mosquitoes are born faster. resulting in breeding as well and causing more mosquitoes to accumulate in nature as well
The normal mosquito life cycle takes regarding 12-15 days, but in this global warming, the mosquito life cycle is shortened to only a few weeks.
In addition, higher air temperature also affects the metabolism of adult mosquitoes, causing mosquitoes to have more flight activity and to be hungry more often. It seeks for the blood of its prey more often, which is why the disease brought by mosquitoes increases.
Mosquitoes carry many diseases.
There are many types of mosquitoes in Thailand. The species found as vectors are Aedes aegypti and Aedes aegypti. carrier of dengue fever fever, joint pain, mosquito bites and Zika virus infection, Anopheles mosquito carrying malaria, Tiger mosquito carrying elephantiasis and mosquitoes annoy the belly carrier of encephalitis Each species of vector mosquitoes has different biological habits and breeding sites.
mosquito killing spray It is a quick and effective way to control mosquito-borne infectious disease outbreaks. Because the purpose of spraying is to kill the infected mother mosquitoes to die quickly.
If the spray does not work It will become more of a public health problem. because there will be a delay in disease control causing the number of patients to increase more than they should have And medical personnel have a lot more responsibility in caring for patients.
While the relevant agencies have to find a way to get rid of mosquitoes that More effective to fight once morest the bad mosquitoes, and people have to find more ways to protect themselves from mosquitoes.
11 ways to “retard-prevent” insecticide-resistant mosquitoes
Dr. Piti said that Thailand has some “mosquitoes” that are strong and resistant to insecticides. It is found in areas where pesticides are overused. without concern that It will be a residual pollution in nature and may cause mosquitoes to become resistant.
In particular, the resistance that occurs is often found in “pyrethroid” insecticides because they are widely used chemicals. because it is a relatively safe group for users people and pets, the smell is not strong and the effect lasts for a very long time
However, it may not be a good idea to use only one pyrethroid insecticide as a single chemical with a single mechanism of action over a long period of time carries the risk of exposing mosquitoes to it. Experience and learn the mechanism of action in the body of mosquitoes. until developing into pyrethroid-resistant mosquitoes Therefore, the following recommendations should be followed to delay and prevent the occurrence of super-mosquitoes in the country.
In addition, Dr. Piti also advised people to make mosquito spray from dishwashing liquid for their own use at home. To kill mosquitoes and annoying mosquitoes that live in our homes. In order to help control mosquitoes participantly and help reduce annoying mosquitoes that come out to disturb our daily life in the evening as well.
Dr. Piti said that increasing the intensity of insecticides Or switch to a stronger brand to get rid of the spray. But it is the same substance that mosquitoes used to tolerate or resist. Over time, mosquitoes will be able to adapt and become more resistant to these thicker insecticides without difficulty.
Therefore, when there is an insecticide resistance problem, we should change the substance group to use another group that mosquitoes are not yet resistant. And use until the stubborn mosquitoes are gone. Then they can go back to the same group of chemicals that are resistant to mosquitoes once more, while the use of harsher chemicals may affect other organisms as well.
However, the choice of chemicals and concentrations should be selected. as recommended by the World Health Organization And has been registered by the Food and Drug Administration (FDA) not spraying too often unnecessarily To prevent the resistance of mosquitoes to chemicals. which this will affect Future disease control efficacy
