Mosquito Control and Prevention

Mosquito First

The annoying buzz of mosquitoss can quickly ruin a warm summer evening outdoors with friends. Nowhere is spared. Every state in the US is home to at least a few species of these annoying pests.

At least 176 species are found in the US, with new ones reported regularly. Nine new species have been recorded in Florida alone in the last decade.

Mosquitos are irritating pests but not every species bites nor do they all carry disease. Several live in habitats that rarely bring them into contact with humans. But when they do, mosquitoes are the most deadly animal on the planet.

There has been a massive growth in mosquito numbers over the past few decades. This has been linked to rural development and population expansion rather than climate change. However, the increase in mosquito-related diseases has been associated with a rise in temperatures and, in some states, rainfall.


Description

Mosquitoes are members of the order Diptera, true flies, meaning they have two wings. The insect’s shape is distinctive, with long legs and a slender body.

Many kinds of mosquito are similar in appearance and hard to differentiate. Both male and female adults are normally brown although a few species have black and white markings on their bodies and legs.

In the majority of mosquitoes, males have feathery antennae and look more fragile than the females. Males feed on nectar or plant sap, lacking the mouthparts to pierce skin.


Life Cycle

All mosquitoes need standing water to complete their life cycle, but habitat preference may vary by species. Some only require water as shallow as a quarter of an inch to breed. This ability to multiply in such a small amount of water makes them a difficult pest to control.

Mosquitoes go through four stages of development: egg, larva, pupa and adult.

Many types of mosquito lay their eggs, frequently numbering a hundred or more, in rafts on the surface of the water. The larvae from these may hatch within one or two days. Other species lay their eggs at the water line or nearby damp soil, where they can survive the dry or even freezing conditions for months. As soon as the water level rises the larvae hatch, often in unison.

Mosquito larvae live in water, feeding on algae, plankton, and other small organisms. Despite their aquatic life, they need to breathe air so most have a siphon at their rear through which they breathe. Hanging down in the water has given rise to their common name of wrigglers.

After four skin changes, the wriggler will be about half an inch long and ready to pupate. The length of time spent in the larval form depends on temperature and species but can be as short as four days.

The pupae, unlike those of many insects, can move and are called tumblers due to the way they fall through the water when disturbed. They quickly rise to the surface again to breathe through two small tubes. The pupal stage is normally brief, sometimes as little as two days.

An adult female’s lifespan can be anything from a few weeks to several months but the males typically live only a week.

Mosquitoes may overwinter as eggs or dormant adults.


Feeding habits

Only female mosquitoes feed on blood, which they need for egg production. Females can detect suitable prey from about 30 yards.

Woodland Mosquito

They find their victims through a combination of clues. These include body warmth and certain chemical signals, such as carbon dioxide, skin odor, and lactic acid. This variable combination is why some people are bitten more often than others in the same location.

With few exceptions, mosquitoes are not powerful flyers and strong winds will deter them from traveling far. Even in calm conditions, the majority will fly less than a mile to search for food, with most venturing less than a few hundred yards.

Mosquitoes don’t only bite in the evening or at night, many species feed during daylight hours.


Diseases

For most people, mosquito bites are irritating yet harmless. The small red bump and itching are caused by a reaction to the pest’s saliva but usually disappear quickly.

Not everyone is as fortunate. Some are allergic to the proteins in the saliva and may experience significant swelling and bruising when bitten. A small number may even suffer serious side effects, including breathing difficulties and, in severe cases, anaphylactic shock.

The saliva of a mosquito plays a crucial role in the transmission of small parasites and viruses. It is these hitchhikers in their saliva that make mosquitoes such a dangerous pest.

When the insect bites an infected person or animal, the minute parasites are drawn into the mosquitoes gut. There they grow until passed back through the saliva into another victim.

The time taken for the parasite or virus to develop within a mosquito until it can be transmitted varies, but mostly takes a week or two. Climate change is allowing female mosquitoes to live longer before the cold weather arrives and kills them. This gives viruses and parasites an extended period to grow and to spread. And with warmer weather enabling mosquitoes to travel further north than before, the diseases are spreading.

Malaria and dengue are regularly reported in the US but the number of cases is relatively low. They are mainly linked to travelers returning from infected areas overseas.

Other diseases carried by mosquitoes include encephalitis, meningitis, Chikungunya, and Zika. West Nile Virus is the most common mosquito-transmitted disease in the US. Tens of thousands of victims of this encephalitic virus have been reported around the country, with the exception of Hawaii and Alaska.

Eastern equine encephalitis is less common but more dangerous, with up to 30% of victims reportedly dying.

Aside from humans, pets and farm livestock can be infected with mosquito-borne diseases. Heartworm has become a serious threat to dogs in all states. It is caused by minute roundworm larvae being transmitted via a mosquito’s saliva.

Eastern equine encephalitis, as the name suggests, is a danger to horses as well as people.


Treatments

Both the Center for Disease Control (CDC) and the US Environmental Agency (EPA) collaborate in mosquito-control activities around the country. State and local agencies also run campaigns to minimize the threat from these pests.

Tackling mosquitoes is usually done in two ways, preventative and with pesticides.

Where possible, potential breeding places such as swamps, ponds, and ditches are drained. Homeowners are encouraged to empty or remove anything containing stagnant water. Due to the small amount of water needed for mosquitoes to breed, these actions may limit the numbers but not eradicate the insect entirely.

Mosquito Third

Larvicides are applied to bodies of standing water and may be in tablet, powder or granular form. For large bodies of water, they will be sprayed onto the surface of the water.

These chemicals will kill the wrigglers but are used in sufficiently low doses that fish are not harmed. The chemicals include pesticides that poison the larvae or insect growth regulators (IGRs) to interrupt their life cycle.

Controlling adult mosquitoes is done with adulticides. These are generally dispersed with an ultra-low volume spray or fogger. When used correctly, these can have a big impact on depleting the mosquito population. Various factors can affect their success, such as temperature, rain, and the wind.

Adulticides are also sprayed in larger droplets on vegetation and walls where adult insects congregate.


Do-It-Yourself Treatments

Preventing mosquitoes from having a place to breed is a key way of reducing their numbers.

The yard should be kept clear of anything that can hold enough water to support a colony of wrigglers, such as cans or plastic bags hidden under a bush. Pot plant containers need regular checking for standing water outside the house and indoors. Keep gutters clear of leaves. Ponds and water features should be treated.

In areas with large numbers of mosquitoes, cover all windows and doors with screens.

If mosquitoes become a problem, there is a wide selection of sprays available on the market. Most contain insecticides, such as DEET, so the instructions should be carefully followed. If used outdoors, the wind normally disperses the spray before it kills a reasonable number of mosquitoes, so the effect may be minimal.

Various traps are marketed to control flying pests in the home. These include electrocutor traps, electronic devices, and light traps. Others claim to mimic the carbon dioxide emissions that attract mosquitos. Although such devices are popular, careful research should be done before buying them. Little scientific data has been published to verify their effectiveness.


Professional Treatments

Professional pest exterminators will use both larvicides and adulticides to protect the homeowner from mosquitoes.

There are strict laws regulating the poisons and chemicals which are used for fogging or for spraying ponds and large bodies of standing water. Expert pest controllers will know the right one for a specific species, season and location.

Some exterminators offer a service based on a set number of visits. These will cover treatments during the worst of the mosquito season, which for most of the country is from May to October. Others take into account environmental factors such as heavy rainfall or drier summers to gauge how often to visit.

A few pest control companies offer ‘natural’ repellent sprays, such as various oils of garlic, cloves, or cedar wood. Check the EPA website to ascertain how effective these products are before signing any agreements. Citronella is another natural product widely marketed. There is little evidence of its effectiveness and the EU has banned its use as a pesticide because of this.


Costs

DIY costs are normally low. They range from a few dollars for a DEET-based spray, to over $100 for combination kits that include larvicides and pump sprays for the adults.

Professional pest control costs will depend on the type of treatment, property size and the frequency of visits. They typically range between $300 and $600 a year.