Winnipeg Free Press - PRINT EDITION
Posted: 06/18/2013 1:00 AM | Comments: 0
Last Modified: 06/18/2013 12:28 PM | Updates
More hot and sunny weather will kill off what remains of Winnipeg's nuisance mosquitoes - but cooler and wetter weather will bring more bugs.
The weather will determine whether Winnipeg's Insect Control Branch will need to fog for mosquitoes for the first time in three years, city entomologist Taz Stuart told reporters today.
The city-wide average trap count for adult female mosquitoes is 15. The city-wide average needs to be 25 or higher for two consecutive days - and one quadrant needs an average of 100 or more - before a fogging program may commence.
In 2012, warm and dry weather killed off a spring emergence of adult nuisance mosquitoes, which tend to die off when the temperature exceeds 25 C.
On Monday, the average trap count in Winnipeg was 21 adult mosquitoes, according to the city's insect control branch. On Friday, the citywide average trap count was four mosquitoes.
Nuisance mosquito species such as Aedes vexans are not known to transmit diseases to people. The last time the city fogged for nuisance mosquitoes was 2010, an unusually buggy summer when the malathion-fogging program ran from June 19 to Sept. 6.
If trap counts rise high enough to warrant fogging this year, the city will test a product called Pyrocide ULV 7067, a biological alternative to malathion, an organophosphate that's toxic to a wide spectrum of invertebrates.
Pyrocide is reputed to have a smaller impact on the environment because it breaks down more quickly and can be effective in smaller concentrations. According to a product monogram, Pyrocide's active ingredients are one part pyrethrin -- a neurotoxin derived from chrysanthemum plants -- and five parts piperonyl butoxide, a sassafras derivative that increases the killing power of insecticides by turning off the enzymes that help mosquitoes fight off chemical attacks.
Pyrocide is also twice as expensive as malathion by volume, however. The insect control branch will apply it to one quarter of the city's insect management areas if a fogging program is warranted and compare the effectiveness to areas treated by malathion.
Malathion must still be used for all areas of the city this summer if the province orders a fogging program to combat West Nile virus, which is carried by species such as Culex tarsalis.
Are you OK with spending more money for a product that’s less harmful to the environment? Join the conversation in the comments below.
Republished from the Winnipeg Free Press print edition June 18, 2013 A7
Updated on Tuesday, June 18, 2013 at 6:45 AM CDT: adds photo, adds question for discussion
12:28 PM: Malathion must still be used if the province orders a fogging program to combat West Nile virus
Having problems with the form?Contact Us Directly
Hundreds take part in Labour Day march
Suspects sought after Osborne Village assault
Mix of sun and cloud today, but risk of showers tonight
Mounties rescue hikers
Manitoba woman dies in B.C. highway collision
Cause of electrical fire still unclear: Hydro
Man charged after stabbing puts another man in hospital
Wet and cool today, sunny on Labour Day
Power-line fire shuts down Main Street
River can't dampen celebration
Teen adds name to trustee ballot
Bailey's owners proud of old-world charm
What I learned working at the Free Press
Missing in action: Wasylycia-Leis has kept a low profile this campaign
Some online readers perplexed by poll results
Things to Do
Sunday horoscope august 31
Downtown outage causes 1,400 to lose power
RCMP investigate knife assault at Selkirk bar
Prairie Barge Festival brings Manitoba, Saskatchewan artists to The Forks
Stabbing in Weston area sends man to hospital
Approaching cars will be a no-no
Thoughts from those with their hands out
Long weekend to see mix of showers and sunny skies
Finding our voice: A primer on the Manitoba dialect
Blaze razes West Hawk landmark
Scientists back in Winnipeg
Teen denied bail in nightclub shooting
Judge slaps cable's Marty
Damaged bridge divides a town
New kitchen, less distress
Moose-hunting ban expanded in Manitoba
Sniffing out zebra mussels
Spat over who will step down
A familiar tragedy