Mosquitoes are more than annoying little buzzing insects that fly around you on a warm summer night, they’re vectors of major human diseases. Mosquitoes are one of the most profoundly adaptable creatures on the planet, with more than 3,000 known species worldwide, and more than 175 species in the United States. This diversity means it is critically important to understand the various species of mosquitoes and their behavior to develop effective control methods. Trying to control mosquitoes without knowing which species are causing problems can severely hamper your efforts, not only reducing the mosquitoes you try to control but also transmitting more diseases.
The Diversity of Mosquito Species
Though there are more than 3,500 described species of mosquito worldwide, only around 140 of them bite, and just a handful of them are responsible for the majority of human disease and mortality caused by mosquitoes. Understanding diversity can help to identify which species might be most amenable to control. You are most likely to see some of the following mosquito species in your life.
Aedes aegypti
- Appearance: Overall small black mosquitoes with white striped legs and lyre-shaped thorax markings.
- Behavior: Day-biting – female mosquitoes feed in the early morning and late afternoon. Breeding – in clean, stagnant water, for example, flower pots, old tires, and water storage containers.
- Disease Transmission: Responsible for transmitting diseases like dengue fever, Zika virus, and chikungunya.
Aedes albopictus
- Appearance: Fierier than Ae aegypti; more white markings on legs; thorax notched, while on Ae aegypti it is just waved.
- Behaviour: He’s also known as the Asian tiger mosquito, and rears those young ones in similarly small, clean collections of water. He’s also a day-feeder.
- Transmits: Various viruses, including dengue fever and chikungunya. Can potentially transmit Zika.
Anopheles mosquitoes
- Appearance: Larger mosquitoes with distinct, long palps that are as long as their proboscis.
- Behaviour: They’re usually most active from dusk to dawn, and prefer to breed in swamps, ponds, slow-moving streams, and other bodies of unpolluted water.
- Disease Transmission: Primary vectors of malaria.
Culex mosquitoes
- Look: They’re usually brown and less conspicuous, and they’re more uniform in appearance than Aedes mosquitoes.
- Behavior: Culex mosquitoes bite at dusk and during the night. During the day, they hide in shaded areas. They breed in different water bodies, ranging from well-maintained water, such as water from tanks, to the illicit type of water often found in dirty gutter systems.
- Disease Transmission: Known to transmit West Nile virus, as well as filariasis.
Tailoring Control Methods
1. Source Reduction
Perhaps the most effective form of control is source reduction, by eliminating breeding sites, and this will depend on the type of mosquito. For example:
- Aedes aegypti and Aedes albopictus: These mosquitoes tend to breed in small, clean pools of water that can be like the water that accumulates in a bird bath, flower pot, or gutter. Disposing of or cleaning out any containers that hold rainwater will lower your risks of exposure to these species. If you cannot avoid having rainwater containers, then covering them to prevent mosquitoes from laying eggs will help as well.
- Anopheles mosquitoes: They lay their eggs in larger amounts of standing water. Ensuring that there are not any areas with standing water around swamps and ponds, and clearing out these bodies of water periodically can reduce breeding.
- Culex mosquitoes: These mosquitoes normally lay their eggs in standing water in sewers that are polluted, slow-moving streams, ponds within or near houses, old tires, catch basins, accepted, septic tanks, and untreated or infrequently treated septic systems. Improving public health, community cleaning, treating backlot systems, and clearing drainage ditches lessen their breeding areas.
2. Biological Control
Natural predators can be used to control mosquito population levels in an approach known as biological control. This can work well with certain species.
- Mosquitoes: Aedes and Culex: release mosquito-eating fish such as Gambusia (mosquito fish) which can decrease the number of larvae.
- Anopheles mosquitoes: Larger bodies of water can be stocked with larvivorous (larva-eating) fish, while smaller larval habitats – such as pint-sized pools in our backyards – can be eradicated by biological agents such as Bacillus thuringiensis israelensis (Bti), which attack only mosquito larvae, not other wildlife.
3. Chemical Control
Chemical control methods comprise a spectrum of insecticides. The chemical used depends on the target mosquito species and its life stages:
- Aedes mosquitoes: apply insecticides to kill the adult mosquitoes: use Mosquito Dunks or another type of pyrethroid or neonicotinoid insecticide, and larvicides at breeding sites.
- Anopheles mosquitoes: invest in larvicides as well as adulticides. Insecticides that target adults of disease-transmitting mosquitoes when they are emerging and are at their most vulnerable to mosquito killers would minimize the chances of malaria transmission.
- Culex mosquitoes: Adulticide sprays can be an effective treatment, especially where these mosquitoes are common. For larvicides, breeding sites can also be dosed to prevent mosquitoes from developing.
4. Environmental Management
Environmental management involves altering the environment to make it less conducive to mosquito breeding:
- Aedes and Culex mosquitoes: Engage in community-wide clean-up programs that remove refuse and rubble that might hold water Properly manage stormwater and sewage to reduce potential breeding areas.
- Anopheles mosquitoes: To control potential breeding sites in wet areas, review your drainage and land use practices where flooding is likely.Block water bodies or alter them to make them less attractive to mosquitoes.
5. Personal Protection
Personal protection measures can help reduce mosquito bites and the risk of disease:
- Aedes mosquitoes: Wear long-sleeved clothing and use mosquito repellents with DEET or picaridin. Use mosquito nets if you will be sleeping in places where these mosquitoes are present.
- Anopheles mosquitoes: Use insect repellents and sleep under insecticide-treated nets to prevent malaria.
- Culex mosquitoes: These mosquitoes feed at night, wear protective clothing and repellent, and set up sleeping areas under screens or nets.
Monitoring and Evaluation
Effective mosquito control requires ongoing monitoring and evaluation:
- Surveillance: Look for mosquito populations and incidence of disease in your area regularly to keep track of the local epidemiology and the progress of your control efforts. Adjust them accordingly.
- Community education: raise mosquito awareness for the community, and residents with interventions and methods to reduce mosquito breeding sites and personal protection. Community buy-in is essential for successful mosquito control programs.
Different species of mosquitoes are associated with different periods. That’s another major reason why when planning control methods, it’s important to know what species of mosquitoes you are dealing with. By targeting the particular species and their particular timing, it’s possible to drastically reduce their populations. Use both source reduction and biological control as well as chemical control, environmental management, and personal protection strategies, and you have the makings of a mosquito control program. Remember, the strategies must be sustained, also, and the public must be engaged in the control or management of the mosquito so the strategies will be continued. They are long-term strategies best aimed at long-term control of these hated, elusive, and sometimes deadly insects.
