Mosquito Control

Property owners NOT wanting insecticides applied on or adjacent to their principal residence may register a buffer zone with the City of Morden. A buffer zone of 90 meters on either side of the objectors property in the front street, side street and rear lane will be established in which fogging equipment will be turned off. To register a buffer zone please email call 204.362.3999 or visit the Access Event Centre at 111 Gilmour St. Please include your full name and civic address and contact information in the request. Buffer zone registration deadline will be indicated at the time a public notice of fogging is released.



What type of Mosquitos cause West Nile Virus?

There are many species of mosquitoes but they mainly fall into two categories, namely the Culex Tarsalis mosquitoes and nuisance mosquitoes. All are a nuisance of course, but it is the Culex Tarsalis mosquito that we need to be concerned about, because it is this species of mosquito that can transmit the West Nile Virus. The City has a mosquito larviciding program in place to combat the nuisance mosquitoes, which started in May of 2006. Before 2006 the City had to have authorization before beginning, but now Council has agreed to combat the problem early. Before the City had to have confirmation from the Province that an infected bird had been found in our area before they could begin the process and thus qualify for funding. The Community Services Department conducts periodic informal larvae counts in an effort to determine approximate numbers. In addition to this, Manitoba Health would set up a number of mosquito traps in our community and they test them for the Culex species on a regular basis. This type of monitoring will still continue.

What is used in the laviciding process?

The pesticide currently being used is comprised of a bacterium that occurs naturally in soils, and therefore it has a minimal impact to people and the environment. This larviciding program is the most effective method of control because it kills the mosquito before it reaches the adult stage and before it begins laying eggs.

What can the public do to help?

  • Report any dead Crows, Blue Jays, Magpies or Ravens to Health Links 1-888-315-9257. (They will come out and pick it up.)
  • Reduce standing water by: Regularly cleaning your eaves troughs, pool covers etc. Cleaning and emptying bird baths on a weekly basis. Ensuring that rain barrel openings are covered with screening. Checking that your yard is clear of debris, toys, bowls or tires that can hold water.

What is fogging and how is it done?

A truck mounted ULV (Ultra-Low Volume) sprayer would be used to spray a mixture of pesticide and water throughout the community. ULV sprayers dispense very fine aerosol droplets that stay aloft and kill mosquitoes on contact. At present, the only registered product for fogging mosquitoes (also known as adulticiding) is Malathion. Please note that the concentration of pesticide being dispensed is very low, and therefore the risk of exposure by people and the environment is minimized.

What would the costs be for a fogging program?

If the City were to voluntarily carry out an adulticiding program (without an order to do so from the province), the local taxpayer would assume all costs for the program. An estimate of the costs for adulticiding is approximately $2,000 per application.

What is involved in adding a fogging program to the larviciding program?

Before the City can begin voluntary adulticiding, it must ensure that all requirements of the provincial Pesticides Regulation (#94/88 R) and the conditions that are placed on our permit are followed. Some of the specific conditions required by the City’s permit are as follows:

  • The City cannot fog unless tests indicate that nuisance levels have reached a minimum of one bite per minute over a ten minute period.
  • The City must provide notice to the public (through the newspaper and/or radio) at least 24 hours in advance of the commencement of fogging. Special attention is paid to beekeeping operations.
  • The City cannot fog flowering plants when honeybees are active.
  • The City must compile a list of residents who object (in writing) to the use of pesticides. Adulticiding equipment must then be turned off within 100 meters (328 feet) on any side of the objector’s property.

What happens when the Provincial Government Orders the City to Fog?

If the City of Morden is ordered by the Provincial Authorities to conduct a fogging for mosquitoes – there is not a lot of notice. The City would place advertisements on the radio, a message on the LED Sign, a message on the welcome page of the website as soon as notice was received. Fogging usually starts at 9:30 pm on the date specified and continues ’till 5:00 am the next morning. Weather Permitting. If weather conditions do not allow fogging to take place when planned it will be pushed forward to the same time period the following evening. The product Malathion, which is registered for mosquito control, will be used. Fogging would take place in the City of Morden as well as a 3 kilometer extended treatment area around the City. MAP – Fogging Treatment Area 2014 (1 MB PDF) Fogging Malathion Questions & Answers(26 KB PDF)

Precautions That The Public Can Take During Fogging;

Health Canada has concluded the use of malathion for adult mosquito control in residential areas using ultra-low-volume application will not pose a health concern. However, people who wish to further reduce their exposure to malathion can take additional precautions which are;

Before spraying occurs:

  • Central air conditioning units may remain on. Window air conditioning units may also remain on, but set the vents to “closed” or choose the “re-circulate” option. If you have an older window air conditioning unit that does not have these options, the air conditioner should be turned off to reduce the possibility of exposure to malathion.
  • Remove children’s toys, outdoor equipment and clothes from outdoors.
  • Pick home grown fruits and vegetables you expect to eat soon before spraying takes place. Rinse home grown fruits and vegetables (in fact, all produce) thoroughly with water before cooking or eating.
  • Cover outdoor tables and play equipment before spraying or wash them off with detergent and water after they have been sprayed.
  • Bring pet food and water dishes inside, and cover ornamental fishponds to avoid direct exposure.

During spraying:

  • Stay indoors and keep your windows closed for at least 30 minutes after the spraying takes place. This is especially important for children and pregnant women, and for those with asthma or other respiratory conditions.
  • Keep pets indoors.
  • If you come in direct contact with malathion spray, protect your eyes.
  • If you get malathion spray in your eyes, immediately rinse them with water.
  • Wash exposed skin.
  • Wash clothes that come in direct contact with spray separately from other laundry.

After spraying:

  • Minimize your contact with surfaces and wash skin that has come in contact with surfaces.
  • Take extra precautions with infants and small children when outdoors by placing children on a blanket instead of the grass.
  • If children’s toys or other items remained outside at the time malathion was applied, wash all items with soap and water before using them again.
  • If you have a vegetable garden, wash vegetables with water before eating them.

Weekly average trap counts of Culex tarsalis by regional health authority will be available on the province’s West Nile Virus website at Updated information on the risk of West Nile virus will be provided to the public thoughout the summer. Manitobans can check the West Nile virus website regularly for up-to-date data and information.