Larval Stage
Source Reduction:

The most effective mosquito control effort is directed toward the source: standing water where larval stages of the mosquito are found. Mosquitoes are extremely vulnerable during the larval stages because of their relatively dense concentrations and the limited protection shallow breeding waters offer. Periodic treatment of all catch basins and storm drainage areas, woodland and vernal pools, freshwater swamplands and meadows, wastewater treatment and settling ponds, ditches, and other man-made or natural depressions and containers will significantly reduce mosquito breeding in suitable habitats. Areas identified as supporting breeding mosquitoes are either targeted for source reduction through habitat disruption, when possible, or biorational larvicide treatments.

Habitat Disruption:

It is possible to prevent mosquito breeding in some normally suitable areas by creating unfavorable environmental conditions in the habitat. Methods include restoring water flow, improving drainage and introducing natural predators such as infectious spores and mosquito fish. All Habitat Services will identify suitable areas and identify possible intervention methods for consideration during the season.



Bti (Bacillus Thuringiensis subsp. israelensis):

This naturally occurring microbe is an extremely effective agent used in controlling a wide species range of mosquito larvae. After Bti is introduced to the larval habitat, it migrates through the water column where it is ingested by larvae in the 2nd and 3rd instar stages. Within hours the spore reacts to alkaline enzymes present in the larval gut, stimulating production of a protein crystal. The crystal rapidly gains in size causing a critical compromise in the integrity of the larval gut wall.


Granules provide up to 14 days of mosquito control in continuously wet habitats and even longer under intermittently dry conditions. They are capable of penetrating dense vegetation and can be applied by hand or granular application equipment. typical treatment areas include storm drainage areas, woodland and vernal pools, freshwater swamplands and meadows, ditches, and other man-made or natural depressions and containers.

Vectolex FG® (Bacillus sphaericus):

This naturally occurring microbe is extremely effective agent used in controlling a wide species range of mosquito larvae. Vectolex FG® is particularly effective in controlling mosquito larvae in waters high in organic matter such as catch basins, animal waste lagoons, and stagnant ponds. It provides the industry’s most target-specific biorational for residual control of West Nile virus vectors.

Catch Basin Treatment Program:

Catch basins and storm drainage areas are highly productive breeding habitats for several species of mosquitoes. Treatment of all catch basin and drainage areas with Vectolex FG® approximately four times per season will control this source.




Chemical adulticide applications provide immediate control of airborne adult mosquito populations. All Habitat Services uses three pyrethroid-based adulticide products, Scourge® (Resmethrin), Bifenthrin®, and Pyrethrin to suit a variety of treatment applications. Scourge® and Pyrethrin are fast acting short residual products which provides quick knock down. Bifenthrin® is an encapsulated product that provides a significantly longer residual effect. All products, at the application rates used, are specifically targeted toward mosquitoes, gnats (noseeums) and black flies. The Bifenthrin/Pyrethrin combination is also effective in controlling ticks. Spray applications will not harm non-target organisms, although care must be exercised to avoid spray drift over water.

Adulticide treatments are recommended when adult mosquito populations reach peak levels. ULV truck treatments cover all properties along roads. Mistblower spray treatments target specific harborage areas on individual properties.

ULV Fog Treatments

Application of Scourge® (Resmethrin) mosquito adulticide ULV spray treatments will provide an immediate knockdown of active mosquitoes and gnats (noseeums) over a large area. The ULV spray mist will also, penetrate vegetation and drift to control resting mosquitoes downwind. Scourge® residues will dissipate within 4 hours of direct sunlight.

Mist Blower Barrier Treatments

Mosquito Adulticide Spray Application Using Backpack Spray EquipmentApplications of Bifenthrin® and Pyrethrin  mosquito adulticide will provide an   immediate knockdown of all active mosquitoes, gnats (noseeums) and small biting flies in the treated area. Treatment of lawns, trees and vegetative borders around breeding sites, upland resting areas and specific high-use areas will create a protective barrier to control resting and migrating mosquito populations for an extended period. Bifenthrin® residues are microencapsulated and will remain effective on trees and vegetation for approximately 4-8 weeks depending on environmental, climate and weather conditions.