t’s reassuring to know that when the mosquitoes return to Headingley this summer there will be fogging brigades on standby ready to deal with the dastardly little devils.
Or is it?
Some say fogging is just a, uh, smoke screen.
Entomologist Rob Anderson of the University of Winnipeg says fogging the way we do it is largely ineffective.
Some of the reasons for that have to do with the nature of the beast. Er, insect.
There are over 3,500 species of mosquito. Many species don’t bite. Some don’t carry diseases and even among those that do, they may have sub-strains that carry different diseases or none at all.
Habits may vary wildly among species that do bite. Some may attack humans only in forested areas, others only in houses.
Some mosquitoes only come out in the morning, some only at night, some only in the afternoon.
Only females are bloodsuckers. (Ahem.)
Then there’s the matter of wind. Mosquitoes eliminated in one area may be replaced quickly by others blown in from elsewhere. In experiments, it’s been found that marked mosquitoes have been trapped 16 kilometres from their release location within 48 hours.
Only some of the myriad mosquitoes out there are airborne and killed when fogging takes place. Within a couple of days, the mosquito count can be up to where it was before fogging.
Anderson says that to be effective fogging has to be done "aggressively and repeatedly." But no one seems to want to put out the money and resources to do this.
So why do it at all?
He says that the sight of fogging trucks "brings solace to a portion of the population" who demand action on the mosquito file. It gets ratepayers off city hall’s back.
Like the city, Headingley fogs only intermittently. It doesn’t wipe out the menace, and a smaller swarm of mosquitoes is still a swarm of mosquitoes. Fogging isn’t worth the cost.
Especially when the chemicals being blasted into the environment may be injurious to human health. Even the latest chemical weapon in the city’s mosquito-killing arsenal, pyrocide, has a suspected carcinogenic ingredient.
Headingley uses propoxur, or methoxychlor. Methoxychlor is no longer registered for use in Canada, and propoxur is "out of favour" because it "operates against an enzyme critical (to) the nervous system."
"Larviciding is the most effective" method of mosquito control. Headingley does participate in the Capital Region Larviciding program and that’s the proper basket for our eggs. Um, resources.
Bob Holloway is a Headingley resident and a community correspondent for Headingley.