Understanding Mosquitoes Life Cycle and Their Control Measures

Mosquitoes are one of the most deadly insect living in our planet. They cause numerous diseases, some of which are fatal. It is important that we protect ourselves and keep our surrounding clean to reduce the population of mosquitoes around our home and office. We may also use mosquito repellents that keep mosquitoes at bay due to their fragrance. Though not all mosquito repellents are effective, but the one with DEET provide protection of about six to eight hours. For young babies you can use plant mosquito repellent for babies age less than 2 years. In order to eliminate mosquito population in your area, you need to first understand the life cycle and their breeding habits. The life cycle of mosquitoes can be divided into four distinct and separate phases: Egg, Larva, Pupa, and Adult. Every one of these phases is identifiable by certain special characteristics. Most adult female mosquitoes feed on an animal for a blood meal before developing eggs. Listed below are the 4 different phases in the life cycle of mosquitoes.
Mosquito bites
Egg
Mosquitoes lay eggs either one at a time or joined together to form “rafts.” Usually, eggs float on the top of water surface. The eggs of Culex and Culiseta species stick together in rafts of about 200. Ochlerotatus, Aedes, Anopheles , and several other genera lay their eggs singly. Anopheles, Culiseta, and Culex lay their eggs on the surface of water while Ochlerotatus and Aedes lay their eggs on moist soil likely to be flooded by water. Usually, eggs hatch into larvae in 2 days; others withstand harsh winters before hatching. Water is an indispensable part of the mosquito habitat.

Larva
Larvae live in the water and come to the water surface to breathe. Usually, larvae molt (shed) their skins 4 times. They grow larger with each such molting of their skin. Larvae of most mosquito species have siphon tubes. Larvae hang upside down inside water and use siphon tubes for breathing. Anopheles larvae don’t have siphons. They lie parallel to the surface of water and draw in their oxygen supply through an opening for breathing. Mansonia and Coquillettidia larvae attach to plants for their air supply. Larvae feed on organic matter and microorganisms in the water. The larva changes during the fourth molt into a pupa.

Pupa
Mosquito pupae, known as “tumblers”, live in water for 1 to 4 days. This phase varies depending upon temperature and species. Being lighter than water, pupae float at the surface of water. Pupae take oxygen through “trumpets”, two breathing tubes. When disturbed, pupae dive into water in a tumbling, jerking motion and later float back to the water surface. The pupal phase of the mosquito is the non-feeding, resting phase of development. The metamorphosis into an adult mosquito takes place inside the pupal case. Splitting the pupal case, the adult mosquito (imago) emerges to the water surface. Here, it rests while its body dries and hardens.

Adult
The newly emerged adult mosquito rests on the water surface. The wings dry and harden in a short while. Only when the wings are completely dry, the adult mosquito can fly. Mating and blood feeding occur in adult mosquitoes after a few days of emerging from the pupal case. Female Anopheles mosquito is the sole mosquito species transmitting malaria to man. The duration of each phase in the mosquito life cycle depends hugely on temperature and species characteristics. For example, Culex tarsalis, a typical California (USA) mosquito, goes through its life cycle within 10 days at 80º F. However, the same species of mosquito takes 14 days at 70º F to complete its life cycle. On the contrary, several species of mosquitoes have adapted to pass through their whole life cycle in fewer than 4 days or as long as 30 days.

Using Mosquito Repellent Effectively

Published data indicate that repellent efficacy and duration of protection vary considerably among products and among mosquito and tick species. Then there is oil of lemon eucalyptus, or PMD, a natural oil extracted from the leaves and twigs of the lemon-scented gum eucalyptus plant, also recommended by the CDC. Many people assume that the more deet (N, N-diethyl-meta-toluamide) a product contains, the better. In many regions across the US, local mosquito control districts engage a range of strategies to reduce mosquito-borne disease risk. Product efficacy and duration of protection are also markedly affected by ambient temperature, level of activity, amount of perspiration, exposure to water, abrasive removal, and other factors.

  • PMD is the ingredient in the oil that makes it repellent to insects.
  • But our tests found that products with 15 to 30 percent deet can provide long-lasting protection against mosquitoes and ticks.
  • These may include broad scale insecticide use or the release of “mosquito fish” into derelict backyard pools.
  • In general, higher concentrations of active ingredient provide longer duration of protection, regardless of the active ingredient.
  • When researchers from New Mexico State University tested a variety of commercial products for their ability to repel mosquitoes, they found that a product containing lemon eucalyptus oil was about as effective and as long lasting as products containing DEET. “For some people, there’s a stigma to using chemicals on their skin.
  • And some research suggests that higher concentrations and excessive doses can pose risks, including rashes and possibly even disorientation and seizures.
  • However, the first line of defense against biting mosquitoes remains the use of topical insect repellents.

Mosquito Control Repellents
Plant based mosquito repellent
Products with <10% active ingredient may offer only limited protection, often 1–2 hours. Mosquitoes are attracted to people by the scent of several chemicals we produce: lactic acid and 1-octen-3-ol, two skin compounds produced by our metabolism and sweating, and carbon dioxide, which we exhale. That’s why we say you should avoid repellents with more than 30 percent deet, and not use it at all on babies younger than two months. For longest protection, synthesized active ingredients such as DEET and picaridin can last 4 to 10+ hours; see product labels for time estimates. Products that offer sustained-release or controlled-release (microencapsulated) formulations, even with lower active ingredient concentrations, may provide longer protection times. One interesting study from New Mexico State University published open access in the Journal of Insect Science found differences in results between Aedes albopictus and A. aegypti, the two species of mosquito that are most likely to carry these diseases, with albopictus less attracted to the test subject’s hand. But not all mosquito repellents are equal. If you prefer to keep it natural, you’ll need to reapply often.

DEET bases mosquito repellent
Permethrin-containing products (Permanone) are recommended for use only on clothing, shoes, bednets and camping gear—never on skin. There are over 60 individual repellent formulations currently registered including aerosols, creams, lotions, pump sprays, wipes, wrist bands and sticks. Repellents using essential plant oils are believed to be effective for 30 minutes to 2+ hours. Permethrin does kill mosquitoes and ticks and is highly effective. Despite this diversity of products, there are only a handful of active ingredients, the most common of which are DEET (diethyltoluamide) and Picaridin.
Permethrin-treated clothing repels and kills ticks, mosquitoes and other arthropods. It remains effective even after repeated laundering. Permethrin-treated clothing should be safe when label directions are followed. Permethrin products should never be applied to the skin. It is often helpful to use spray repellents on outer clothing as well as the skin. Protection times vary. Repellents such as DEET that are used on the skin will be effective for anywhere from 90 minutes to 10 hours, depending on the amount of active ingredient in the product and skin condition.

Controlling Mosquito population

The development of effective vaccines and their massive application, together with the successful results of mosquito control programmes in the recent past, have reduced the disease to a fraction of its overall global importance half a century ago. Mosquitoes need water to live. Many mosquito problems in your neighborhood are likely to come from water-filled containers that you, the resident, can help to eliminate. Biological control is the use of natural enemies to manage mosquito populations. The threat of a sudden epidemic remains ever present, however, and measures have to be taken to cope with this eventuality.

  • They lay their eggs near or on standing water.
  • All mosquitoes require water in which to breed.
  • There are several types of biological control including the direct introduction of parasites, pathogens and predators to target mosquitoes.
  • Programmes of chemical control of Aedes mosquitos have somewhat suffered from the difficulties encountered with other vector mosquitos; there is thus a corresponding need to instigate alternative methods of control.
  • The egg hatches into a larva in the water.

Be sure to drain any standing water around your house. The Placer Mosquito and Vector Control District employs mosquitofish (Gambusia affinis), a predatory fish that feeds on mosquito larvae. Depending on the location in New Hampshire and conditions that determine the risk for EEE/WNV transmission, initial application of larvicides take place during the last two weeks of April and through mid-May of any given year. The larva becomes a pupa, and then finally becomesa flying adult mosquito, usually in 1 – 3 weeks. Choose a mosquito repellent that has been registered by the Environmental Protection Agency.

Mosquito Source Reduction
Mosquito control begins with daily population tracking. Follow-up applications may take place periodically afterward, and after heavy rains. The adult female mosquito then needs to bite an animal or human for blood so that she can produce eggs and repeat the lifecycle.Mosquito control programs use many ways to control mosquitoes. Registered products have been reviewed, approved, and pose minimal risk for human safety when used according to label directions. Trapping, biting counts and client service requests all provide information upon which control decisions are based. hey try to get rid of standing water in cities and in the country where mosquitoes will lay eggs. Always follow instructions when applying insect repellent to children. Do not use insect repellent on babies younger than 2 months of age. Dress your child in clothing that covers arms and legs, or Cover crib, stroller, and baby carrier with mosquito netting. Do not apply insect repellent onto a child’s hands, eyes, mouth, and cut or irritated skin. Surveillance tells us about species composition, abundance, gauges control efforts, and provides a historical perspective.
Mosquito Pest Control
They add mosquito-eating fish to ponds to eat the larvae and pupae. Surveillance initiates the control decision, but considerations such as weather, public exposure, environmental sensitivity and timing determine whether or not controls are applied. Liquid larvicide products are applied directly to water using backpack sprayers and truck or aircraft-mounted sprayers. Without a well-designed sampling and surveillance program, it is diffi cult to know what is really going on with mosquitoes in your community. Tablet, pellet, granular, and briquet formulations of larvicides are also applied by mosquito controllers to breeding areas. Knowing what species of mosquitoes are active provides clues as to where breeding is occurring and whether public health is threatened. While there are a number of registered active ingredients used in larvicides, below you will find information on more commonly used larvicides. In addition to monitoring mosquito population changes, surveillance programs may monitor the presence of health-threatening viruses in wild animal and bird populations. This information is useful in determining whether and when spraying is needed, and allows health departments to issue health alerts and target awareness programs to affected parts of the community.

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