A significant rainfall event will usually trigger a mosquito management program

Mosquito control relies on understanding the biology of the species involved, knowledge of its habitats, and constant monitoring of the control area. Our most successful method for reducing mosquito populations is to target the immature stages of their life cycle when they are most vulnerable.

In the Edmonton area, where mosquitoes are primarily a nuisance rather than a disease problem, adult control is generally not practiced. Since 1974 the City's mosquito control program, developed by the University of Alberta, has targeted larval stages of nuisance species. Experience has shown that targeting the larvae is a more proactive, environmentally-friendly, effective, and safer approach than controlling adult mosquitoes. In general, our control programs drastically reduce the production of nuisance mosquitoes within the City's control boundaries.

Comprehensive monitoring programs throughout this zone identify treatment needs which vary with the impact of snowmelt and summer rainstorms. The amount of rainfall can result in anything from no action at all to a region wide ground based larviciding operation.

Treatment Methods

Edmonton’s mosquito control program utilizes a larvicide product containing Bti, a selective fly gut toxin derived from bacteria (Bacillus thuringiensis israelensis). Summertime post-treatment surveys show that application of Bti reliably manages most populations of larval mosquitoes. Bti has been used by Edmonton’s mosquito control program since 1980.

Off-road sites and ditch habitats along road allowances are treated by the City's ground based delivery equipment. Applications are restricted by:

  • Mosquito development beyond the fourth larval instar since these are no longer susceptible to the treatments available
  • Windy or rainy conditions
  • Inaccessibility due to terrain conditions or landowner refusal

Larvicides are applied only to temporary or semi-permanent bodies of water containing larvae. Permanent bodies of water are not treated because they contribute little toward nuisance mosquito production. Additionally, these habitats support more complex insect communities including mosquito predators like dragonflies.

Treatment campaigns are terminated with the development of pupal stages of the mosquito which can appear in as little as a week to ten days after hatching. Information about spraying activities and adult mosquito populations is publicized through media releases and interviews.

Key Dates In Edmonton's Battle Against Mosquitoes

  • 2021 - Transition to an entirely ground based program (aerial program using helicopters discontinued)
  • 2020 - First confirmed detection of the northern house mosquito (Culex pipiens), a common West Nile disease vector.
  • 2020 - Transition from New Jersey Light Traps to BG-Sentinel CO2 traps for mosquito activity monitoring.
  • 2020 - Fully implemented near real-time automated rain gauge network, replacing manual system.
  • 2018 - Implemented GPS technology to track and report aerial and roadside applications; began development on GPS system to track granular backpack applications.
  • 2018 - Transition completely to a biorational pesticide program.
  • 2018 - Implemented UTVs (utility task vehicles) for off-road treatments
  • 2012 - Implemented mobile devices in the field to map standing water and collect larval mosquito development and population data in near real-time.
  • 2003 - West Nile virus found in Alberta. The province initiated a three-year funding program for mosquito vector detection and source reduction.
  • 1994 - Implemented a cost-saving efficiency with a one-person ditch crew versus two-person.
  • 1993 - Discontinued mosquito adulticide program (fogging) targeting the city's river valley and ravine system.
  • 1993 - Provincial funding assistance eliminated (approximately 50% of budget); eventually all surrounding municipalities discontinued mosquito control in the capital region.
  • 1993 - Implemented global positioning (GPS) technology to assist helicopter pilots in identifying “no fly” areas such as noise-sensitive farming operations.
  • 1991 - Initiated mosquito development site reduction (landfill) program.
  • 1980 - Introduction of bacterial control product (Bti) for usage in sensitive areas.
  • 1975 - Edmonton's district operated mosquito program was centralized under a single pest control unit.
  • 1973 - Mosquito control monitoring laboratory started.
  • 1972 - Spraying DDT for mosquitoes was discontinued.
  • 1953 - Aerial mosquito control initiated.