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 the water in a birdbath every seven days or entail extensive drainage practices to reduce the amount of stagnant water available.
Prevention (Larvicide) – Mosquito Control District
Prevention activities are the primary method of killing immature, non-flying, and non-biting mosquitoes in their water habitats and reducing or modifying mosquito-breeding habitats. Mosquito Larvicide applications are prioritized since this type of control is more selective and effective in reducing mosquito populations. This mosquito control measure requires personnel, equipment, materials, planning, surveillance work, and expense. However, these types of applications offer the best long-term control for mosquitoes.
Bacillus thuringiensis israelensis (Bti) is used as a mosquito larvicide and is applied to mosquito breeding areas when mosquito larvae are 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 number of mosquito breeding sites where we live. Remember that one female can lay 250 eggs in one batch and within one week those can turn into 250 adult mosquitoes in your backyard. Proper source reduction benefits us all.
Relatively calm water for at least 4 days is necessary for the mosquito lifecycle. The good news is that anything you can do to interrupt this process can stop mosquitoes. 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 a practical approach because the larvae are somewhat isolated, and known breeding sites can be recorded and routinely monitored. For many districts, this is the bulk of their operations. There are several different products available for abatement practices. Often, one product will be better suited for a particular situation than another.
Larvicides We Use:
VectoMax WSP (Bacillus Sphaericus, Bacillus Thuringiensis Israelensis): specific for mosquito larva
VectoBac G (Bacillus thuringiensis subsp. israelensis (strain AM65-52) specific for mosquito larvae
Vectomax FG (Bacillus Sphaericus, Bacillus Thuringiensis, (subsp) israelensis
Natular G30 WSP (Spinosad (a mixture of spinosyn A and spinosyn D)
- Bacillus Sphaericus/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 (poly-alpha –w-hydroxy):
- A monomolecular surface film used for later stages of larva and pupa 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
MetaLarv XRP (s) Methoprene
- A biorational, extended release pouch for pre-hatch & standing water control of mosquito larvae in catch basins & drainage systems.
Altosid Pellets WSP (S-Methoprene)
- 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 typical development cycle resulting in the inability to complete their metamorphosis.
Adulticides
Adulticiding is controlling mosquitoes when they are mature, flying mosquitoes. Adult female mosquitoes bite, ultimately providing the most significant threat to 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, we cannot treat some areas so mosquitoes can develop without our interference. Adulticiding can temporarily control mosquitoes in a given area but is not practical as the only control method
Adulticides We Use:
PermaSease 4-4 – fogged at a rate between 0.001 and 0.007 pounds per acre
- Permethrin/Piperonyl Butoxide . It is a man-made version of the natural botanical insecticide, pyrethrin.PermaSease 4-4 offers excellent effectiveness against adult mosquitoes, low mammalian toxicity, low odor and rapid bio-degradability.
Biomist 4+4 – fogged at a rate 0.00175-0.007 pounds per acre
- The active ingredient in Biomist® is an IRAC Class 3A synthetic pyrethroid called permethrin. It emulates the naturally derived botanical insecticides, known as pyrethrins, found in chrysanthemum flowers. In all Biomist formulations, permethrin is combined with a synergist, piperonyl butoxide (PBO), to enhance its ability to provide fast knockdown and control of wild mosquito populations.
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 can be used: label specifications, mosquito population size and species make-up, and expected temperature range.