Mosquitoes have mutated to resist insecticide
Mosquito populations are quite high in one section of the planet.
One of our planet's most detested bugs continues to survive despite human efforts to eradicate it.
According to recent research, "super mosquitos" have evolved to withstand pesticides, with the most "surprising" outcome being a high incidence of mutations in a species known to spread disease.
Researchers from Japan's National Institute of Infectious Diseases analyzed mosquitos in dengue-endemic areas of Vietnam and Cambodia and discovered that they possessed mutations that gave them high resistance to popular pesticides, according to a report published Wednesday in Science Advances.
According to the study, one of the most concerning changes was found in almost 78 percent of the collected Aedes aegypti specimens, one of the most common mosquito species and a significant transmitter of dengue, yellow fever, and Zika viruses.
According to the article, the development of pyrethroid resistance often happens when mutations occur in the Vgsc gene, which encodes the molecular target of pyrethroids. The researchers uncovered ten novel Aedes aegypti subtypes and determined that one Vgsc mutation, L982W, provided great resistance to the pyrethroid pesticide permethrin in laboratory mosquitos.
This mutation was found in more than 79% of mosquitos collected in Vietnam, while Cambodian mosquitos possessed combinations of L982W and other Vgsc mutations that demonstrated "severe" pyrethroid resistance, according to the researchers.
The L982W mutation has yet to be detected outside of Vietnam and Cambodia, but experts believe it is steadily spreading to other regions of Asia.
According to the researchers, the findings might pose a severe danger to infectious disease management and eradication operations because the mutation represents one of the highest rates of pesticide resistance seen in a mosquito population in the field.
Many public health programs employ pyrethroids and other pesticides to combat mosquito-borne illnesses, particularly those for which no vaccine exists, such as dengue fever.
"It's critical to understand that the pesticides we often use may not be effective against mosquitoes," study author Shinji Kasai, a senior researcher at the NIID's Department of Medical Entomology, told ABC News.
These mutant alleles must be regularly watched, particularly in Southeast Asia, so that necessary actions may be implemented before they spread globally, Kasai added. Furthermore, Kasai stated that cycling various pesticide groups is occasionally beneficial.
"Health officials should select the most appropriate and effective mosquito control pesticide," he stated.
Mosquitoes appear to have adapted to evade human eradication efforts, both physically and instinctively.
Scientists conducted a research in February demonstrating that mosquitos learn to avoid the chemicals used to control them.
Scientists studying two mosquito species, Aedes aegypti and Culex quinquefasciatus, discovered that females learnt to avoid insecticides after a single non-lethal treatment.
Mosquitoes have mutated to resist insecticide: FAQs
What happens if an insect becomes genetically resistant to pesticides?
If an insect becomes genetically resistant to a particular pesticide, it means that the pesticide is no longer effective at controlling the population of that insect. This can have serious consequences for agriculture, as the resistant insects can continue to reproduce and cause damage to crops. Pesticide resistance can also have ecological impacts, as the resistant insects may alter the balance of their ecosystem by surviving and reproducing more successfully than other insects that are sensitive to the pesticide.
To mitigate the effects of pesticide resistance, it is important for farmers to use a variety of pest management strategies, including cultural, physical, and biological methods in addition to pesticides. Rotating the use of different pesticides and using them in combination can also help to slow the development of resistance. Additionally, monitoring for the presence of resistant insects and implementing appropriate management strategies can help to control their populations and prevent the spread of resistance.
What causes resistance to insecticide?
Insects can become resistant to insecticides through a process called evolution by natural selection. When a population of insects is exposed to an insecticide, some individuals may have genes that provide resistance to the chemical. These resistant individuals are more likely to survive and reproduce, passing on their resistant genes to their offspring. Over time, the proportion of resistant individuals in the population may increase, leading to the development of a resistant population.
There are several factors that can contribute to the development of insecticide resistance, including:
High frequency of use: If a particular insecticide is used frequently and consistently, it can increase the selective pressure on the insect population and accelerate the development of resistance.
Lack of diversity in pest management strategies: Using a single pest management strategy, such as a single insecticide, can also increase the selective pressure on the insect population and lead to the development of resistance.
Genetic variability: Some insect species have naturally high levels of genetic variability, which can increase their potential to evolve resistance to insecticides.
Cross-resistance: Insects that are resistant to one insecticide may also be resistant to other insecticides that have a similar mode of action.
Migration: Insects can migrate from one location to another, potentially spreading resistant genes to new populations.
Increased reproduction: Insects that reproduce rapidly may have a higher potential to evolve resistance to insecticides, as they can generate many generations in a short period of time.
What insect is most resistant to pesticides?
It is difficult to identify a single insect species that is most resistant to pesticides, as resistance can vary widely within and between different species. Some examples of insects that have been found to have high levels of resistance to certain pesticides include:
Houseflies: Houseflies (Musca domestica) are known to be resistant to many different insecticides, including organophosphates, carbamates, and pyrethroids.
Mosquitoes: Mosquitoes (Culicidae) are known to be resistant to many different insecticides, including organophosphates, carbamates, and pyrethroids.
Cotton bollworms: Cotton bollworms (Helicoverpa armigera) are a major pest of cotton crops and have been found to be resistant to many different insecticides, including organophosphates and pyrethroids.
Bed bugs: Bed bugs (Cimex lectularius) are resistant to many insecticides, including pyrethroids, which are often used to control them.
Beetles: Many species of beetles, including Colorado potato beetles (Leptinotarsa decemlineata) and cotton boll weevils (Anthonomus grandis), have been found to be resistant to insecticides.
It is important to note that insects can develop resistance to pesticides over time, and the level of resistance can vary within and between different populations of the same species. Therefore, it is not possible to identify a single insect species that is universally resistant to all pesticides.
What is the most common form of insecticide resistance?
One of the most common forms of insecticide resistance is metabolic resistance, which occurs when insects have enzymes that can detoxify or break down the insecticide before it can have an effect. This can occur through a process called enzyme induction, where the insect produces more of the detoxifying enzymes in response to exposure to the insecticide. Metabolic resistance can also be inherited, meaning that the resistant genes are passed on from one generation to the next.
Other forms of insecticide resistance include target-site resistance, in which the insect's target site for the insecticide is altered, and behavioral resistance, in which the insect changes its behavior to avoid exposure to the insecticide.
It is also common for insects to develop resistance to multiple insecticides at the same time, a phenomenon known as cross-resistance. This can occur when the insecticides have a similar mode of action or when the same detoxifying enzymes are involved in breaking down multiple insecticides.
It is important to note that the specific type and frequency of insecticide resistance can vary widely within and between different insect species.
What is the most widely used insecticide in the world?
The most widely used insecticide in the world is likely pyrethroid, a synthetic chemical that is similar to the naturally occurring pyrethrins found in certain plants. Pyrethroids are widely used in agriculture, forestry, and public health programs to control a variety of insects, including mosquitoes, flies, ticks, and beetles. Pyrethroids are known for their low toxicity to mammals and are considered to be relatively safe for use around humans and pets.
However, pyrethroids can be toxic to certain non-target organisms, including fish and birds, and they can also have negative impacts on beneficial insects, such as honey bees. In addition, some insects have developed resistance to pyrethroids, which can limit their effectiveness. For these reasons, it is important to use pyrethroids and other insecticides responsibly and to implement a variety of pest management strategies to minimize the risks to non-target organisms and reduce the potential for resistance to develop.
What did farmers do before pesticides?
Before the widespread use of synthetic pesticides, farmers used a variety of cultural, physical, and biological methods to control pests. These methods, which are often referred to as integrated pest management (IPM), can be effective at reducing pest populations and minimizing the need for chemical pesticides.
Cultural methods involve altering the growing conditions to make them less favorable for pests, such as rotating crops, using resistant varieties, and practicing proper sanitation to remove pest habitats. Physical methods involve using physical barriers or traps to control pests, such as using netting to protect crops from insects or using sticky traps to capture flies. Biological methods involve using natural predators or parasites to control pest populations, such as releasing predatory insects or birds to control pest insects or using biological pesticides, which are derived from natural substances such as bacteria or fungi.
Farmers have also used various chemical substances to control pests for centuries, including plant-derived compounds such as pyrethrins and nicotine, as well as minerals such as sulfur and copper. However, the development of synthetic pesticides in the 20th century greatly expanded the range of chemical options available to farmers, leading to their widespread use in agriculture.