Tuesday, June 30, 2015


Signs have appeared in the park indicating that mosquito larvae spraying has recently occurred.  The two signs are next to standing water in a ditch adjacent to the path and next to one of the four inner ponds of the wetland complex.  FOSS was concerned, particularly about spraying the wetland ponds, and approached the City for an explanation.

Toronto Public Health responded in this way .......

"Surface water pools are regularly monitored by staff and are only treated once the presence of mosquito larvae is detected.  BTi is used to treat these pools and is a highly specific biological bacterium that kills the larvae within a matter of hours.   This product is not harmful to humans, pets, wildlife and fish.
TPH has two vector borne disease field operators who monitor surface water locations for mosquito breeding.  When a site is identified they conduct larvae dipping to determine the presence of larvae and take samples back to the office to verify vector species for WNv.  When a location is identified that requires treatment, a referral is made to our contracted service provider (Pestalto) for montioring and treatment.  Pestalto holds a permit with the MOE and have licensed applicators to apply the larvicide.  The product used is a biological larvicide (derived from naturally occurring soil bacteria) which breakdown quickly in the environment and are harmless to plants, mammals, fish, birds and insects other than mosquitoes and blackflies.  Please see our website for further information."
Although there appears to be no real danger to the spraying, it seems a little unusual to refer to a wetland pond as a "field pool" and aren't mosquito larvae part of a food chain?  Just saying.

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