Mosquito control manages the population ofmosquitoes to reduce their damage to human health, economies, and enjoyment. Control strategies range from habitat modification and chemical insecticides to biological agents and mechanical traps. Rising global temperatures have expanded mosquito habitats and disease risks, prompting a greater focus on community-led education programs to play key roles in reducing breeding grounds and tracking mosquito populations.
Mosquito-control operations are targeted to multiple problems:
Disease organisms transmitted by mosquitoes includeWest Nile virus,Saint Louis encephalitis virus,Eastern equine encephalomyelitis virus,Everglades virus,Highlands J virus,La Crosse encephalitis virus in the United States;dengue fever,yellow fever,Ilhéus virus,malaria,Zika virus andfilariasis in theAmerican tropics;Rift Valley fever,Wuchereria bancrofti,Japanese encephalitis,chikungunya and filariasis in Africa and Asia; andMurray Valley encephalitis and Ross River fever in Australia.Vertical transmission from adult mosquitos to larvae is possible.[1]
Depending on the situation, source reduction, biocontrol,larviciding (killing oflarvae), or adulticiding (killing of adults) may be used to manage mosquito populations. These techniques are accomplished using habitat modification,pesticide, biological-control agents, and trapping. The advantage of non-toxic methods of control is they can be used inconservation areas.
Integrated pest management (IPM) is the use of the most environmentally appropriate method or combination of methods to control pest populations. Typical mosquito-control programs using IPM first conduct surveys, in order to determine thespecies composition, relative abundance and seasonal distribution of adult and larval mosquitoes, and only then is a control strategy defined.
Adult mosquito populations may be monitored by landing rate counts, mechanical traps, or bylidar technology.[2][3] For landing rate counts, an inspector visits a set number of sites every day, counting the number of adult female mosquitoes that land on a part of the body, such as an arm or both legs, within a given time interval. Mechanical traps use a fan to blow adult mosquitoes into a collection bag that is taken back to the laboratory for analysis of catch. The mechanical traps use visual cues (light, black/white contrasts) or chemical attractants that are normally given off by mosquito hosts (e.g.,carbon dioxide,ammonia,lactic acid,octenol) to attract adult female mosquitoes. These cues are often used in combination. Entomology lidar detection has the possibility of showing the difference between male and female mosquitoes.[2]
Monitoring larval mosquito populations involves collecting larvae from standing water with a dipper or aturkey baster. The habitat, approximate total number of larvae andpupae, and species are noted for each collection. An alternative method works by providing artificial breeding spots (ovitraps) and collecting and counting the developing larvae at fixed intervals.[4] Monitoring these mosquito populations is crucial to see what species are present, if mosquito numbers are rising or falling, and detecting any diseases they carry.[4]
Mosquito Alert is a cooperativecitizen science project, currently run as anon-profit and coordinated by four public research centers in Spain.[5] The aim of the project is to study, monitor, and fight the spread of invasive mosquitos.[6] The project provided the first detection of the Asian bush mosquitoAedes japonicus in Spain in 2018, providing the first report of a population of mosquitos that were located 1,300 km from their previously nearest known location in Europe.[7]
Climate change has enabled mosquitoes such asAedes aegypti andAedes albopictus to spread into new geographic regions, including temperate areas where they were previously unable to survive. Warmer temperatures accelerate mosquito development, shorten breeding cycles, and increase biting frequency, all of which enhance the potential for disease transmission. Shifts in rainfall patterns and the increased frequency of extreme weather events also create more stagnant water sources, which are ideal breeding grounds for mosquitoes. These ecological changes have contributed to the emergence or resurgence of mosquito-borne diseases such asdengue,Zika, andchikungunya in parts of Europe and North America. In response, public health organizations have begun integrating climate-based data,remote sensing, andpredictive modeling into their surveillance systems to monitor habitat suitability and guide early warning efforts for mosquito population surges.[8]
Temperature, humidity, moisture, and rain are some of the weather conditions that affect the mosquito's behavior and activity.[9] Understanding the relationship between climate variables and mosquito ecology is now considered a key component of proactive vector control strategies.
The following municipalities, territories, and countries have regulations concerning removal of standing water to prevent mosquito breeding:
A 2010 study in New Jersey evaluated how community participation can improve mosquito control through source reduction.[32]AmeriCorps volunteers were trained to identify and explain mosquito breeding sites such as planters, rain barrels, and discarded containers. These peer educators visited over 750 homes, offering active, on-site education. Compared to control areas, the communities that received active outreach saw a 22.6% decrease in unmanaged container habitats.[33] Additional events liketire disposal and trash can modification days encouraged long-term engagement. The study found that community-driven efforts led to measurable behavior change, particularly when residents had hands-on involvement.
Recent research has explored the use of robotics andartificial intelligence to improve mosquito surveillance. The "Dragonfly" robot,[34] developed in Singapore, uses a deep learning algorithm calledYOLO V4 (You Only Look Once version 4) to detect and classify mosquitoes. It can identifyAedes aegypti,Aedes albopictus, andCulex species from glue traps with an accuracy of up to 88% in offline tests and 82% in real-time field trials.[35] The robot maps mosquito detections on a two-dimensional grid, helping researchers visualize population hotspots. This automated approach reduces the need for manual identification and supports faster response times in high-risk areas.
Mechanical control is the management and control using physical means.
Since many mosquitoes breed instanding water, source reduction can be as simple as emptying water from containers around the home. This is something that homeowners can accomplish. Mosquito breeding grounds can be eliminated at home by removing unused plasticpools, oldtires, orbuckets; by clearing cloggedgutters and repairing leaks aroundfaucets; by regularly (at most every 4 days) changing water inbird baths; and by filling or draining puddles, swampy areas, and tree stumps. Eliminating such mosquito breeding areas can be an extremely effective and permanent way to reduce mosquito populations without resorting to insecticides.[36] However, this may not be possible in parts of thedeveloping world where water cannot be readily replaced due to irregular water supply. Many individuals also believe mosquito control is the government's responsibility, so if these methods are not done regularly by homeowners then the effectiveness is reduced.[37]
Open water marsh management (OWMM) involves the use of shallow ditches, to create a network of water flow within marshes and to connect the marsh to a pond or canal. The network of ditches drains the mosquito habitat and lets in fish which will feed on mosquito larvae. This reduces the need for other control methods such aspesticides. Simply giving the predators access to the mosquito larvae can result in long-term mosquito control.[38] Open-water marsh management is used on both the eastern and western coasts of the United States.[citation needed]
Rotational impoundment management (RIM) involves the use of large pumps and culverts with gates to control the water level within an impounded marsh. RIM allows mosquito control to occur while still permitting the marsh to function in a state as close to its natural condition as possible. Water is pumped into the marsh in the late spring and summer to prevent the female mosquito from laying her eggs on the soil. The marsh is allowed to drain in the fall, winter, and early spring. Gates in the culverts are used to permit fish, crustaceans, and other marsh organisms to enter and exit the marsh. RIM allows the mosquito-control goals to be met while at the same time reducing the need for pesticide use within the marsh. Rotational impoundment management is used to a great extent on the east coast of Florida.[39]
A 2019 study also explored the idea of usingunmanned aerial vehicles as a valid strategy to identify and prioritize water bodies wheredisease vectors such asNy.darlingi are most likely to breed.[40]
An oil drip can or oil drip barrel was a common and nontoxic anti-mosquito measure.[41][42][43][44][45][46] The thin layer of oil on top of the water prevents mosquito breeding in two ways:[47] mosquito larvae in the water cannot penetrate the oil film with their breathing tube, and so drown and die; also adult mosquitoes do not lay eggs on the oiled water.
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A traditional approach to controlling mosquito populations is the use ofovitraps orlethal ovitraps, which provide artificial breeding spots for mosquitoes to lay their eggs. While ovitraps only trap eggs, lethal ovitraps usually contain a chemical inside the trap that is used to kill the adult mosquito and/or the larvae in the trap. Studies have shown that with enough of these lethal ovitraps,Aedes mosquito populations can be controlled.[48] A recent approach is the automatic lethal ovitrap, which works like a traditional ovitrap but automates all steps needed to provide the breeding spots and to destroy the developing larvae.[49]
In 2016 researchers fromLaurentian University released a design for a low cost trap called anOvillanta which consists of attractant-laced water in a section of discarded rubber tire. At regular intervals the water is run through a filter to remove any deposited eggs and larva. The water, which then contains an 'oviposition' pheromone deposited during egg-laying, is reused to attract more mosquitoes. Two studies have shown that this type of trap can attract about seven times as many mosquito eggs as a conventional ovitrap.[50][51][52][53]
Some newer mosquito traps or known mosquito attractants emit a plume of carbon dioxide together with other mosquito attractants such as sugary scents,lactic acid,octenol, warmth, water vapor and sounds.[54] By mimicking a mammal's scent and outputs, the trap draws female mosquitoes toward it, where they are typically sucked into a net or holder by an electric fan where they are collected. According to the American Mosquito Control Association, the trap will kill some mosquitoes, but their effectiveness in any particular case will depend on a number of factors such as the size and species of the mosquito population and the type and location of the breeding habitat.[citation needed] They are useful in specimen collection studies to determine the types of mosquitoes prevalent in an area but are typically far too inefficient to be useful in reducing mosquito populations.[citation needed]
This is a process of achieving sustainable mosquito control in an eco friendly manner by providing artificial breeding grounds with anovitrap[55] or anovillanta[56] utilizing common household utensils and destroying larvae by non-hazardous natural means such as throwing them in dry places or feeding them to larvae eating fishes likeGambusia affinis, or suffocating them by spreading a thin plastic sheet over the entire water surface to block atmospheric air. Shifting the water with larvae to another vessel and pouring a few drops ofkerosene oil or insecticide/larvicide in it is another option for killing wrigglers, butnot preferred due to its environmental impact. Most of the ornamental fishes eat mosquito larvae.[citation needed]
Chemical control is the management and control using chemical means.
Control of larvae can be accomplished through use of contact poisons, growth regulators, surface films, stomach poisons (including bacterial agents), and biological agents such as fungi, nematodes, copepods, and fish.[57] A chemical commonly used in theUnited States ismethoprene, considered slightlytoxic to larger animals, which mimics and interferes with natural growth hormones in mosquito larvae, preventing development. Methoprene is frequently distributed in time-releasebriquette form in breeding areas. Another chemical is Temefos ortemephos, a sand granular insecticide is used to treat water infected with disease carrying insects.
It is believed by some researchers that the larvae ofAnopheles gambiae (important vectors of malaria) can survive for several days on moist mud, and that treatments should therefore include mud and soil several meters from puddles.[58]
Control of adult mosquitoes is the most familiar aspect of mosquito control to most of the public. It is accomplished by ground-based applications or viaaerial application[59] of residual chemical insecticides such asDuet. Generally modern mosquito-control programs in developed countries use low-volume applications of insecticides, although some programs may still use thermal fogging. Beside fogging there are some otherinsect repellents for indoors and outdoors. An example of a synthetic insect repellent isDEET. A naturally occurring repellent iscitronella. Indoor Residual Spraying (IRS) is another method of adulticide. Walls of properties are sprayed with an insecticide, the mosquitoes die when they land on the surface covered in insecticide.[60]
To control adult mosquitoes in India, van mounted fogging machines and hand fogging machines are used.[61][62][63]
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DDT was formerly used throughout the world for large area mosquito control, but it is now banned in most developed countries.[64]
Controversially, DDT remains in common use in manydeveloping countries (14 countries were reported to be using it in 2009[64]), which claim that the public-health cost of switching to other control methods would exceed the harm caused by using DDT. It is sometimes approved for use only in specific, limited circumstances where it is most effective, such as application to walls.[citation needed]
The role of DDT in combating mosquitoes has been the subject of considerable controversy. Although DDT has been proven to affect biodiversity and cause eggshell thinning in birds such as the bald eagle, some say that DDT is the most effective weapon in combating mosquitoes, and hence malaria. While some of this disagreement is based on differences in the extent to which disease control is valued as opposed to the value of biodiversity,[citation needed] there is also genuine disagreement amongst experts about the costs and benefits of using DDT.[dubious –discuss]
Notwithstanding, DDT-resistant mosquitoes have started to increase in numbers, especially in tropics due to mutations, reducing the effectiveness of this chemical; these mutations can rapidly spread over vast areas if pesticides are applied indiscriminately (Chevillon et al. 1999). In areas where DDT resistance is encountered,malathion,propoxur orlindane is used.
| Toxicant | Dosage in g/m2 | Average duration of effectiveness in months |
|---|---|---|
| DDT | 1 to 2 | 6 to 12 |
| Lindane | 0.5 | 3 |
| Malathion | 2 | 3 |
| Propoxur | 2 | 3 |
Mosquitoes are highly adept at locating their human hosts, largely due to their ability to detect specific chemicals present in human body odor. Research has identified several compounds in human sweat and skin that are particularly attractive to mosquitoes. Understanding these attractants is crucial for developing more effective mosquito control methods, including targeted repellents and traps that mimic human odors to lure mosquitoes away from people.[65]
Among these attractants, CO2 and lactic acid are considered the most effective, with CO2 attracting mosquitoes from the longest distances and lactic acid influencing their preference for certain individuals.
Understanding the specific chemicals that attract mosquitoes facilitates the development of innovative control strategies. For example, mosquito traps that emit both CO2 and lactic acid have proven more effective in luring mosquitoes away from human populations, significantly reducing the risk of bites and the spread of diseases. Additionally, personal repellents engineered to mask or chemically alter these attractants can render individuals less detectable to mosquitoes. Integrating these repellents into daily personal care routines, especially in regions prone to mosquito-borne diseases, offers a proactive approach to disease prevention.
Research into the chemical properties of human body odor that attract mosquitoes reveals complex interactions between mosquito host-seeking behavior and human chemical signatures. By deciphering these mechanisms, scientists aim to devise solutions that could substantially reduce the incidence of mosquito-borne diseases. Advances in synthetic biology and nanotechnology are opening new avenues for creating targeted compounds and delivery systems that efficiently combat mosquitoes without harming the environment.
While existing repellents and traps offer temporary solutions, they frequently fall short due to their limited duration of effectiveness and inconsistent efficacy across different mosquito species. For example, many current repellents do not provide all-night protection, and traps might not attract all types of mosquitoes. Future research should prioritize the discovery of new attractant compounds through molecular biology and high-throughput screening methods, aiming to develop more universally effective and durable mosquito control solutions.
Addressing the ecological impacts of widespread use of chemical attractants and repellents is also essential. Careful evaluation is needed to ensure these methods do not harm non-target species or disrupt ecological balances. In practical scenarios, leveraging these insights could transform how we manage mosquito populations and reduce disease transmission. With ongoing technological advancements and deeper understanding of mosquito ecology, we can anticipate the development of next-generation repellents and attractant-based traps that provide robust and environmentally friendly protection against mosquitoes.
Biological control is the management and control using biological means.
Biological pest control, or "biocontrol", is the use of the natural enemies of pests like mosquitoes to manage the pest's populations. There are several types of biocontrol, including the direct introduction of parasites, pathogens, and predators to target mosquitoes. Effective biocontrol agents include predatory fish that feed on mosquito larvae such asmosquitofish (Gambusia affinis) and somecyprinids (carps and minnows) andkillifish.Tilapia also consumemosquito larvae.[66] Direct introduction of tilapia and mosquitofish into ecosystems around the world have had disastrous consequences.[67] However, utilizing a controlled system viaaquaponics provides the mosquito control without the adverse effects to the ecosystem.
Other predators include dragonfly (fly)naiads, which consume mosquito larvae in the breeding waters, adultdragonflies, which eat adult mosquitoes, and some species oflizard andgecko.[68] Biocontrol agents that have had lesser degrees of success include the predator mosquitoToxorhynchites and predatorcrustaceans—Mesocyclopscopepods,[69]nematodes andfungi.[70] Predators such as birds, bats, lizards, and frogs have been used, but their effectiveness is only anecdotal.
Instead of chemical insecticides, some researchers are studying biocides. Like all animals, mosquitoes are subject to disease. Invertebrate pathologists study these diseases in the hope that some of them can be utilized for mosquito management. Microbial pathogens of mosquitoes include viruses, bacteria, fungi, protozoa, nematodes and microsporidia.[71][page needed][72]
Most notably, scientists inBurkina Faso were studying theMetarhizium fungal species. This fungus in a high concentration can slowly kill mosquitoes. To increase the lethality of the fungus, a gene from a spider was inserted into the fungus causing it to produce aneurotoxin. The gene was regulated to only activate when in mosquito hemolymph. Research was done to show the fungi would not affect other insects or humans.[73][74][75][76] Two other species of fungi that can kill adult mosquitoes areMetarhizium anisopliae andBeauveria bassiana.[77]
Dead spores of thesoilbacteriumBacillus thuringiensis, especiallyBt israelensis (BTI) interfere withdipteran larvaldigestive systems. It can be dispersed by hand or dropped byhelicopter in large areas. BTI loses effectiveness after the larvae turn into pupae, because they stop eating.[citation needed] BTI was reported to be widely applied in West Africa with limited adverse effects, and may pose lesser risk than chemical pesticides.[78]
In theWolbachia method,[79] both male and female mosquitos that carry theWolbachia bacterium are released into natural populations.[80]Wolbachia boosts the natural immune response of the mosquito so that it does not easily get infected and become a host vector for mosquito-borne diseases.[81] Therefore it is unable to easily transmit those viruses to people. This is known as replacement strategy as it aims to replace the natural population withWolbachia-carrying ones.[82] Since 2011, theWorld Mosquito Program has conducted several trials and projects, in 14 countries across Asia, Latin America and Oceania.
This approach also usesWolbachia but involves the release of only male mosquitos that carry theWolbachia bacterium. When these male mosquitos mate with wild female mosquitos, her eggs do not hatch due to lack of biocompatibility.[83]Wolbachia is not endemic to wild mosquito populations although it is endemic in 50% of all insect species.[84] This is known as suppression strategy as it aims to suppress the natural reproduction cycle.[85]Wolbachia-Aedes suppression has been piloted in various countries such as Myanmar (1967), French Polynesia (2009, 2012), USA (2014-2016, 2018), Thailand (2016), Australia (2017), Singapore (since 2016) and Puerto Rico (2020).[86]
Maui and Kuai, Hawaii - A series of IIT projects were planned to protect endangered bird species fromavian malaria. The projects involve the release of large numbers of male mosquitos infected with a strain ofWolbachia that is incompatible with the strain carried by resident females. These mosquitos would not be irradiated or subject to genetic modification.[87]
Introducing large numbers of sterile males is another approach to reducing mosquito numbers. This is calledSterile Insect Technique (SIT).[88] Radiation is used to disrupt DNA in the mosquitoes and randomly create mutations. Males with mutations that disrupt their fertility are selected and released in mass into the wild population. These sterile males mate with wild type females and no offspring is produced, reducing the population size.[89]
Guangzhou, China - A combination of SIT with IIT, were used in a mosquito control program in Guangzhou, China. The pilot trial was carried out with the support of theIAEA in cooperation with theFood and Agriculture Organization of theUnited Nations (FAO). The pilot demonstrated the successful near-elimination of field populations of the world's most invasive mosquito species,Aedes albopictus (Asian tiger mosquito). The two-year trial (2016–2017) covered a 32.5-hectare area on two relatively isolated islands in thePearl River in Guangzhou. It involved the release of about 200 million irradiated mass-reared adult male mosquitoes exposed toWolbachia bacteria.[90]
These techniques share the characteristic of introducing lethal genes and reducing the size of the mosquito population over time.
Another control approach under investigation forAedes aegypti uses a strain that isgenetically modified to require the antibiotictetracycline to develop beyond the larval stage. Modified males develop normally in a nursery while they are supplied with this chemical and can be released into the wild. However, their subsequent offspring will lack tetracycline in the wild and never mature.[91] Field trials were conducted in the Cayman Islands, Malaysia and Brazil to control the mosquitoes that cause dengue fever. In April 2014, Brazil's National Technical Commission for Biosecurity approved the commercial release of the modified mosquito.[92][93] TheFDA is the lead agency for regulating genetically-engineered mosquitoes in the United States.[94]In 2014 and 2018 research was reported into other genetic methods including cytoplasmic incompatibility, chromosomal translocations, sex distortion and gene replacement.[95] Although several years away from the field trial stage, if successful these other methods have the potential to be cheaper and to eradicate theAedes aegypti mosquito more efficiently.[96]
A pioneering experimental demonstration of thegene drive method eradicated small populations ofAnopheles gambiae.[97][98]
In 2020,Oxitec's non-biting Friendly Aedes aegypti mosquito was approved for release by the USEPA and Florida state authorities.[99]
Malaysia - In several experiments, researchers released batches of male adult Aedes mosquitos with genetic modifications to study the effects of dispersal and reproduction in natural populations. Mosquito traps were ultilized for the purpose of these studies.[100] The process allowed for the opportunity to determine which mosquitoes were affected, and provided a group to be re-released with genetic modifications resulting in the OX513A variant to reduce reproduction. Adult mosquitoes are attracted inside the traps where they died of dehydration.
Research is being conducted that indicates that dismantling a protein associated with eggshell organization, factor EOF1 (factor 1), which may be unique to mosquitoes, may be a means to hamper their reproduction effectively in the wild without creating a resistant population or affecting other animals.[101][102]
InSingapore, under the Control of Vectors and Pesticides Act there is a legal duty on occupants to preventAedes mosquitos from breeding in their homes. If breeding mosquitos are found by inspectors, occupiers are subject to a fine of 5,000Singapore dollars or imprisonment for a term not exceeding 3 months or both.[103]
Some biologists have proposed the deliberate extinction of certain mosquito species. BiologistOlivia Judson has advocated "specicide" of thirtymosquito species by introducing a genetic element which can insert itself into another crucial gene, to createrecessive "knockout genes".[104] She says that theAnopheles mosquitoes (which spreadmalaria) andAedes mosquitoes (which spreaddengue fever,yellow fever,elephantiasis,zika, and other diseases) represent only 30 out of some 3,500 mosquito species; eradicating these would save at least one million human lives per year, at a cost of reducing thegenetic diversity of thefamilyCulicidae by 1%. She further argues that since species become extinct "all the time" the disappearance of a few more will not destroy theecosystem: "We're not left with a wasteland every time a species vanishes. Removing one species sometimes causes shifts in the populations of other species—but different need not mean worse." In addition, anti-malarial andmosquito control programs offer little realistic hope to the 300 million people indeveloping nations who will be infected with acute illnesses each year. Although trials are ongoing, she writes that if they fail: "We should consider the ultimate swatting."[104]
BiologistE. O. Wilson has advocated the extinction of several species of mosquito, including malaria vectorAnopheles gambiae. Wilson stated, "I'm talking about a very small number of species that have co-evolved with us and are preying on humans, so it would certainly be acceptable to remove them. I believe it's just common sense."[105]
Insect ecologist Steven Juliano has argued that "it's difficult to see what the downside would be to removal, except for collateral damage". Entomologist Joe Conlon stated that "If we eradicated them tomorrow, the ecosystems where they are active will hiccup and then get on with life. Something better or worse would take over."[106]
However,David Quammen has pointed out that mosquitoes protect forests from human exploitation and may act as competitors for other insects.[107] In terms of malaria control, if populations of mosquitoes were temporarily reduced to zero in a region, then this would exterminate malaria, and the mosquito population could then be allowed to rebound.[108]
