October 11, 2020

What’s all the buzz about mosquito abatement in SLC?

What’s all the buzz about mosquito abatement in SLC? Cx. tarsalis) What’s all the buzz about mosquito abatement in SLC? What’s all the buzz about mosquito abatement in SLC? What’s all the buzz about mosquito abatement in SLC? What’s all the buzz about mosquito abatement in SLC?
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By Turner Bitton

As the summer comes to a close, so too does Salt Lake City’s mosquito season. Mosquito abatement (reduction or control), is a public health practice that prevents much more than itchy bites from mosquitoes. It is also key to combating viral threats like the West Nile Virus.

Mosquito abatement is a set of practices that control the spread of mosquitoes. National and international organizations are dedicated to professional development of the people who do this unique work. The American Mosquito Control Association is the preeminent professional organization that fosters international connection between mosquito control professionals from across the globe.

In Salt Lake City, mosquito control responsibility rests with the Salt Lake City Mosquito Abatement District (SLCMAD). Established in 1924 by the Utah State Legislature, the SLCMAD is a special service district, meaning it receives a small portion of property taxes in Salt Lake City for the single purpose of controlling mosquitoes. Members of the Board of Trustees are appointed by the Salt Lake City mayor and confirmed by the city council.

The SLCMAD is headquartered on the West Side in a state-of-the-art facility constructed in 2019. The campus centralizes the many functions of the SLCMAD, including an onsite laboratory to test for West Nile Virus, equipment for the marshy northwest quadrant of Salt Lake City, and an aquaculture facility.

The West View was invited to participate in a ride-along on August 5 with Jason Hardman, the operations supervisor at SLCMAD. On the ride-along we were given a behind-the-scenes tour of their operations, including the state-of-the-art laboratory where testing is done for the West Nile Virus – a type of testing so unique that at the beginning of the COVID-19 crisis, the local health department borrowed equipment from the SLCMAD to support their response.

Testing in mosquito abatement can show not only the prevalence of a virus, but its spread. The on-site aquaculture facility cultivates ITALICS: Gambusia affinis, also known as the Mosquitofish, to help control mosquitoes.

Northwest of the airport in the marsh, we were shown the application of mosquitocide on the surface of the water. This larvicide targets mosquito larvae to eliminate them prior to aging into adulthood. It is applied in a massive area of the city’s northwest quadrant using equipment attached to a four-wheeler.

Following this stage, we drove to a mosquito trap near the proposed Utah Inland Port. Mosquito traps are set up to capture live mosquitoes for subsequent testing in the laboratory or to measure a given population in an area. On the top of the trapping mechanism is a valve that releases CO2 to attract mosquitoes, while a fan on the bottom pulls them into the trap.

Afterwards, we spoke with Executive Director Ary Faraji, PhD, BCE, who is the President of the American Mosquito Control Association. Below is our conversation:

How many different types of mosquitoes does the Salt Lake City Mosquito Abatement District eliminate?

There are over 3,500 species of mosquitoes in the world and about 200 species are found in the United States. In Utah, there are about 50 recognized species of mosquitoes; but, fortunately, only a handful of them are of public health importance.

In Salt Lake City, there are 26 documented species of mosquitoes. However, the vast majority of our surveillance and control efforts are geared towards four species. These species are Aedes sierrensis (the western tree hole mosquito), Aedes dorsalis (our common flood water mosquito), Culex pipiens (the northern house mosquito), and Culex tarsalis (the western encephalitis mosquito).

The larvae of the first species (Ae. sierrensis) thrives in small tree hole habitats (cavities that hold water inside deciduous trees) and loves to bite people and their pets. In fact, this species is the primary vector of dog heartworm in our area.

Aedes dorsalis also loves to bite mammals (which includes us!). But, luckily, this species is not a vector (a carrier of a pathogen) of any mosquito-borne diseases in our area and, hence, only impacts our quality of life by causing nuisance.

Culex pipiens is primarily a bird-biting mosquito, but this species is the primary vector of West Nile virus in our region and primary culprit for introducing and maintaining the virus between birds and mosquitoes annually.

The last species, Cx. tarsalis, is perhaps the most important mosquito that we deal with. This species is not only pestiferous and loves to bite humans and other mammals, but it also opportunistically feeds on birds and is the major vector of mosquito-borne disease in our area.

In short, Cx. tarsalis not only impacts our quality of life but is also of public health importance. I should also note that Ae. sierrensis and Cx. pipiens are mostly suburban and urban species, while Ae. dorsalis and Cx. tarsalis are mostly rural species.

You mentioned that mosquitoes are highly mobile. How does this impact the way that you plan for mosquito control in Salt Lake City?

Generally, the mosquitoes (Ae. dorsalis and Cx. tarsalis) that are produced in the wetland habitats of western Salt Lake City move about a mile a night. SLCMAD’s primary responsibility is to prevent the dispersal of these two species from the wetland habitats into the city, where the vast majority of our residents are located.

Hence, we monitor the abundance (how many mosquitoes are out there), species composition (exactly what species are found), and pathogen infection rates (how many mosquitoes are infected with a virus) of all mosquitoes in our jurisdiction so that we can make scientifically- informed control decisions.

These efforts help guide where we need to conduct additional control measures in order to preserve our residents’ quality of life and protect them from potentially infected mosquitoes that may transmit pathogens.

We encountered multiple duck hunting clubs when we were in the field. How does your relationship with these clubs support your mission?

Mosquito control is not about mosquitoes; it is actually about people. It’s about protecting people, about developing relationships, and about working in solidarity with other groups.

The duck clubs have historically been great partners with our organization for many decades. They provide us access into their private properties, allow us to conduct treatments when/where they are needed, and understand that the surveillance and control efforts that we are conducting are not only for their benefit, but they are also for the benefit of the greater community outside the duck clubs.

Do you anticipate that the proposed Utah Inland Port Authority development area and relocation of the Utah state prison will affect your work?

Yes, absolutely. The port and prison are both being located in primary mosquito habitats. The addition of lights and people will certainly attract more mosquitoes, and more development will demand more control from SLCMAD. We are fortunate to have great partners at the state level, particularly the Department of Administrative Services, who have been working with use to ensure mosquito control needs are being met.

Does the general public have a responsibility in mosquito control?

Mosquito control is a job for everyone. There are many standing water habitats located within private residential properties that can be addressed by the homeowner.

For example, don’t overwater your plants and cause dishes or plant saucers to hold water for extended amounts of time; empty your pet watering bowls and bird baths weekly; cover your rain water collection containers; and don’t leave out wheelbarrows, tires, buckets, or other containers that may collect rain or sprinkler water.

Additionally, if residents have an abandoned swimming pool or a pond, please contact us and we will provide a mosquito-eating fish or treat that habitat to ensure that no mosquitoes are being produced there. This service is provided to all of our residents within Salt Lake City and is of no additional cost to them, so please take advantage of it.

In what ways is climate change impacting the field of mosquito control?

Mosquito control is a very dynamic profession that is constantly changing. Factors such as climate change, epidemiology, biology, ecology, pesticide manufacturing, insecticide resistance, and even human cultural changes can greatly impact the way that mosquito control is conducted.

In general, since insects are cold-blooded and their development and also the amplification of the pathogens that they harbor are greatly affected by temperature, the greater the temperature, the faster their rate of development.

For the most part, warmer temperatures are not only expanding the geographic range of some mosquito species, but they may also increase the rate of pathogen amplification.

To boot, we are also seeing not only geographic expansion in latitude and longitude, but also one in altitude where some species are being found higher and higher in elevation.

How do you measure your success?

[One measurement] is the number of Service Requests that we get in relation to biting mosquitoes in the city. This number has drastically gone down since the introduction of our aerial mosquito control program. We conduct large area-wide applications when mosquito numbers are above our established thresholds, and this is intended to quickly bring down the total number of biting mosquitoes in an area.

Lastly, Jason mentioned that the Salt Lake City Mosquito Abatement District is recognized internationally. What are some of the innovations that you have been able to share with other jurisdictions?

We take great pride in publishing our work and disseminating the information that we gather here to a much larger audience via peer-reviewed publications and also presentations at many meetings across the country.

Some recent innovations include the development, training, and publication of a Best Management Practices booklet for invasive mosquitoes in the USA; the use of unmanned aerial

systems (drones) for mosquito surveillance and control; the utilization of 3D printers for making our own traps (We no longer purchase expensive traps because we design and print them in-house); and responding to and assisting other districts and areas when it comes to mosquito control.