What We Do
Summit Mosquito Abatement District uses an Integrated Mosquito Management (IMM) approach, which is utilizing all available methods and industry best practices, in locating and controlling mosquito populations within Summit County. With this approach, our goal is not the complete eradication of mosquitoes (too costly and intrusive), but to reduce mosquitoes to acceptable levels while minimizing environmental impact. In achieving this approach, the district spends most of its time and resources in four main areas: surveillance, larviciding, adulticiding, and record keeping.
Surveillance
Before taking steps to eliminate mosquitoes, we must first know where they exist, what species are present, the stage of the life cycle, and the habitat conditions. Our field technicians are trained in and conduct effective surveillance techniques so they can properly determine where treatments will occur and at what frequency and intensity.
While out and about, you may have seen one of our technicians walking through a field or yard dipping the water using a long stick with a cup. Well, what technicians are doing is sampling the water to determine the presence of mosquito larval and/or pupae and what life stage and how prevalent they are. Based on their findings, technicians make the appropriate decisions for treatment. Technicians rotate through their area checking each water source about once a week for the larvae and pupae.
In addition to surveying mosquito populations in larval and pupae stages, the district conducts regular surveillance of adult mosquito populations as well. Female mosquitoes use three sets of receptor cell types that are sensitive to carbon dioxide, lactic acid and temperature to
find a blood source. We take advantage of these attractants by using them to lure adult mosquitoes into light (increases temperature) and carbon dioxide traps. The district has 11 standard locations throughout the county where we place light traps. As carbon dioxide traps are much more portable--not requiring a power source--we can place them in any area of the county where adult mosquitoes may be present. Traps are activated during the night and early morning hours when mosquitoes are most active. We collect the contents of traps every day or every other day. The traps' contents are bought into the lab and analyzed for mosquito numbers and species. The district bases its treatment of adults on this analysis. We also collect those mosquito species (i.e., Culex Tarsalis and Culex Erythrothorax) that are known carriers of West Nile Virus (WNV). Once enough of these species are collected, we take them to the Utah Department of Health Lab for testing to determine if any are infected with WNV.
Larviciding
Larviciding is the treatment process of controlling mosquito populations while in the aquatic larval/pupal stage. As it easier and more cost-effective to control mosquitoes in this stage than it is to control adults, larviciding is our preferred treatment method. In addition, larviciding has very little impact on non-target species and their habitat and offers the best long-term control option. Upon finding larvae or pupae in a water source, our technicians analyze treatment needs and make the appropriate application using a horn seeder, a gas-powered spreader, or a backpack oiler. A horn seeder is a canvas bag to which a long metal tube (horn) is attached. Chemical is put into the bag, and the technician, placing the bag on their shoulder, waves the horn to discard the chemical on a water source. The rate at which the chemical comes out is controlled by a gate in the horn and the waving speed. Technicians also use gas-powered, backpack spreaders for larvciding. This equipment allows for the
treatment of larger water sources with more time efficiency. A gate adjustment and motor speed control the rate of application. If pupae exists in the water, technicians use oil or a liquid surfactant as the means of treatment. Pupae are in a non-feeding state and as such the chemicals used in horn seeders or powered spreaders for larval treatment are not effective. Using a backpack sprayer, technicians spread a thin layer of oil or surfactant on the water's surface. This film prevents the pupae from breaching the surface to breathe and causes them to drown. Oil and surfactant are also effective at treating larvae.
Adulticiding
If adult mosquitoes emerge because of ineffective or missed treatments, adulticiding may be necessary. Our district uses large truck-mounted Ultra-Low Volume (ULV) aerosol generators to apply adulticide. These machines produce a fog with a very small droplet siz
e that have a lethal effect on adult mosquitoes. To be most effective, ULV fogging occurs during the evening when mosquitoes are most active. The decision to use ULV foggers is based on result of our surveillance activities. Our district has established in its Pesticide Discharge Management Plan (PDMP) thresholds that determine the need for adulticiding. These thresholds must be triggered before treatment occurs. We understand that some may have concerns about adulticiding including those with health issues, beekeepers, organic farmers, and others with legitimate other concerns about the use of pesticides. Please contact us if you have any questions about the methods or pesticides we use.
Recording Keeping
SMAD uses a robust Global Position System (GPS) system to record all surveillance, larviciding, and adulticiding activities within Summit County. Our system houses every area within the county where our technicians conduct weekly inspections. Each time an inspection occurs the technician's name, the inspection's date and time, and date of the next inspection are recorded. When a treatment is performed, additional information is entered into the system, such as the pesticides used, the amount used, the size of the treated area, treatment time, the life stage present, and the mode of application.