Yard & Garden Pests
Mosquitoes are important insects in Saskatoon. Firstly they are vectors of disease and secondly mosquitoes are nuisance, especially when they come in large numbers. Through our monitoring program, we typically capture 20 different species throughout the season. The most common nuisance mosquito is Aedes vexans and the most common mosquito that can carry the West Nile virus is Culex tarsalis.
Mosquito Control in Saskatoon
What is the City doing to control mosquito population in Saskatoon?
The City’s mosquito control program focuses on efforts to control the aquatic life stage of the mosquito (larvae). We regularly monitor mosquito development sites (small bodies of water) within approximately 945 square kilometres including the City of Saskatoon and a surrounding buffer. The City also monitors the adult mosquito population using New Jersey light traps and Centre for Disease Control light traps. We do this to ensure our control measures are effective and to track the presence of West Nile virus in adult mosquitoes.
How does the City monitor mosquito larvae?
The City’s Pest Management staff are trained in larval identification. To determine if a body of water requires treatment, the staff will sample to determine if larvae are present. When there are at least two larvae per dip an area is treated. This can mean the entire water body or just areas where the larvae were found.
How are larvae treated?
Larval mosquitoes are killed using a biological larvicide called Bacillus thuringiensis var israelensis (Bti or Vectobac®).
How is it applied? Is it dangerous?
The bio-larvicide is a type of bacteria that is applied to the surface of the water using a backpack sprayer. The species of bacteria only affects filter feeding insects and has the greatest impact on mosquitoes and black flies. The bacteria does not persist in the environment and does not harm non-filter feeding insects or any vertebrates.
Does the City tell residents when larvacides are used?
After treatment a sign is often posted to indicate that a pesticide product was used at that location. The sign includes the product that was used and the product registration number. The signs indicate to both the pest management staff and the public that an area has been treated. We also issue letters requesting access to privately owned land in the RM of Corman Park.
What you can do?
Saskatoon residents can assist with reducing mosquito populations by eliminating mosquito habitat on their property. Mosquitoes need water to develop, and their eggs and larvae can develop in any water, even small amounts, that are allowed to stand for four days or more. To aid in the prevention of mosquito breeding:
- Remove any standing or stagnant water from your property.
- Ensure items in and around the property, like pool covers, saucers under flower pots, children's toys, pet bowls and wading pools are regularly emptied or replaced with clean water.
- Clean eaves troughs regularly so water does not collect.
- Empty and clean bird baths twice weekly.
- Ensure that openings in rain barrels are covered with mosquito screening.
- Aerate ornamental ponds and stock with fish that eat mosquito larvae.
- Ensure that your yard is free of debris, such as old tires that can hold rainwater.
You can also take preventative measures to minimize the opportunity for mosquito bites by:
- Wearing long-sleeved shirts and long pants, and applying insect repellent;
- Minimize time spent outdoors between dusk and dawn when mosquitoes are most active;
- Making sure all windows and doors in homes are tight-fitting and properly screened.
West Nile Virus
Mosquito season means the presence of mosquito-borne viruses such as West Nile virus. Questions about West Nile virus can be directed to Saskatchewan Health at 1-800-667-7766 or the City of Saskatoon at 306-975-3300.
How is West Nile Virus spread?
West Nile virus is usually transmitted to people through bites from infected mosquitoes. There are many species of mosquitoes, most of which do not transmit disease. The main carriers of WNv in Saskatchewan is Culex tarsalis.
While mosquito control will provide some protection, it will not eliminate the risk of contracting West Nile virus (WNv). For this reason, residents should protect themselves with mosquito repellents, mosquito netting, or otherwise avoid mosquito bites.
Health Canada recommends the use of repellents containing concentrations of DEET, not to exceed 30% for adults or 10% for children two to twelve years of age. No more than one application of 10% DEET per day is recommended for infants six months to two years old. DO NOT USE DEET on infants under six months.
Some non-DEET repellents have been shown to provide protection for a period of time. Use of these products is recommended instead of DEET for people with:
- Allergic skin reactions to products containing DEET.
- Irritated, sunburned, bruised or broken skin.
- Skin conditions such as skin cancer, dermatitis, acne, eczema or psoriasis.
Wasps play an important role in your yard and garden as pollinators and predators.
What is a yellowjacket?
Yellowjackets are a type of wasp, 15–20mm in length, with yellow and black or white and black stripes on their bodies. They live in colonies, and similar to other social insects, there is a queen, female workers and reproductive males, known as drones. With yellowjackets, only the queen survives the winter, and in early spring she begins construction of a new nest. The nest is usually located in the ground, cracks in pavement or other sheltered places; but some yellowjackets build papery nests in trees. In the nest, the colony grows and in late summer can reach a few hundred wasps. Yellowjackets are beneficial as they kill many garden pests, but will also feed on nectar, pollen and scavenge for many different sources of protein and sugars. Yellowjackets can sting multiple times and are often aggressive when disturbed near their nest.
How to control yellowjackets?
To control yellowjackets, first locate the nest and then wait until evening or early morning to remove the nest. Removing the nest is safer if the nest is first sprayed with a foaming insecticide designed for wasps, but in some situations nests can be removed directly into a garbage bag. If you can’t locate the nest, but want to reduce the number of yellowjackets foraging in your backyard, use hanging wasp traps baited with sugary solutions. Typically, yellowjackets only become a nuisance in late summer, and the workers die in the fall.
If you find a yellowjacket nest on city property, contact the Parks Branch at 306-975-3300.