Control Methods

Prevention and Source Reduction Around the House:

Source Reduction is removing breeding sites or making them inhospitable for mosquitoes. This can be as simple as changing out water in a birdbath every 7 days, or can entail extensive drainage practices to reduce the amount of stagnant water available.

Prevention (Larvicide) – Mosquito Control District
Prevention activities are the primary method we employ to kill immature non-flying and non-biting mosquitoes in their water habitats and to reduce or modify mosquito-breeding habitats.  Mosquito Larvicide applications are given top priority since this type of control is more selective and effective in reducing mosquito populations.  This type of mosquito control measure requires personnel, equipment, materials, planning, mosquito surveillance work and expense.  However, these types of applications offer the best long-term control for mosquitoes.

Bacillus thuringiensis israelensis (Bti) ise used for mosquito larvicide and applied to mosquito breeding areas when mosquito larvae are found in the 1st to 3rd instar life stages.

Although some of the control methods outlined here are limited to Mosquito Control Districts, all of us can take steps to reduce the amount of mosquito breeding sites where we live. Keep in mind that one female can lay 250 eggs in one batch and within one week those can turn into 250 adults mosquitoes in your backyard. Proper source reduction benefits us all.

Relatively calm water that stays around for at least 4 days is an absolute necessity for the mosquito lifecycle. The good news is that anything that you can do to interrupt this process can stop mosquitoes in their tracks. The bad news is that it only takes a little water (as little as 1/4 of an inch), a little food (almost any organic material will do) and a little time (in the right conditions, they can go from egg to adult in 4 days) to produce mosquitoes. So the goal should be to eliminate places where mosquitoes can develop and minimize your exposure to them.

Mosquito Larviciding:

Larviciding is the process of controlling mosquitoes when they are in the larval or pupal form. Controlling mosquitoes when they are in the water is an effective approach because the mosquito is somewhat isolated and known breeding sites can be recorded and routinely monitored. For many districts, this is the bulk of their operations. There are a number of different products available for abatement practices. Often times, one product will be better suited for a particular situation than another product.

Larvicides We Use:


  • Bacillus thuringiensis israelensis (Bti) is a microbe used in controlling mosquito larvae. Mosquito larvae of susceptible species ingest a lethal dose of Bti crystals and spores. Toxins are activated in the larval midgut, paralyzing and damaging the digestive system. Larvae become sluggish and die within 24 hours.

Larvicide & Pupicide

  • AGNIQUE® MMF is a larvicide and pupicide with a unique physical mode of action rather than chemical toxicity. It is ideally suited for mosquito control programs as it can be used in a wide range of habitats from fresh water to salt water and it’s even labeled for use in potable water.


  • Methoprene is an insect growth regulator (IGR) that interferes with normal mosquito development. Methoprene is absorbed through the skin of the larvae and disrupts the normal development cycle resulting in the inability to complete their metamorphosis.


Adulticiding is the process of controlling mosquitoes when they are mature, flying mosquitoes. Adult female mosquitoes are the ones that bite, so ultimately they provide the largest threat to the public welfare. Adulticiding is necessary because larviciding is not 100% effective, some sites may be unknown and mosquitoes can migrate into the District from surrounding areas. Also, there are areas that we cannot treat and so mosquitoes have the opportunity to develop without interference from us. Adulticiding can provide temporary control of mosquitoes in a given area, but is not practical as the only method of control.

Adulticides We Use:

  • AquaReslin AquaReslin is  permethrin and sumithrin products, respectively.  It is a man-made version of the natural botanical insecticide, pyrethrin. AquaReslin offers excellent effectiveness against adult mosquitoes, low mammalian toxicity, low odor and rapid bio-degradability. AquaReslin® is one of  the “least toxic” products registered with the EPA for ULV adult mosquito control. 

These materials have been chosen for their excellent long-term safety record, and their effectiveness in the field. Each material has a specific set of conditions under which it will be used, namely, label specifications, mosquito population size and species make-up, and expected temperature range.


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