Winnipeg Free Press - PRINT EDITION
Skeeter general claims victory
No swarms expected despite heavy rains
In fact, the general in charge of the battle of the bugs doesn't expect much of an assault from the skeeters over the next few weeks despite heavy rains on Saturday and again Monday.
July is traditionally the worst month for mosquitoes, but the extent of the infestation is based on weather conditions in June, city entomologist Randy Gadawski said yesterday.
"If we do have a failure with mosquito control, it's usually a failure of larviciding in June that results in July mosquitoes," he said.
"We don't expect conditions that will allow the situation to get away from us, so we can expect a comfortable next two weeks," Gadawski said.
"The number of adult mosquitoes is really quite low."
City staff haven't even activated mosquito traps -- there simply aren't enough of the pests to count.
To date, there has been no need for residential fogging, either.
In fact, Gadawski hinted the effectiveness of the city's larviciding assault on standing water -- the mosquitoes' breeding ground -- could mean no fogging at all this summer for the first time in five years.
"We've had a stretch where we've fogged every year lately," he said. "But we've never been better prepared early in the season like we are now."
A similarly confident prediction was made at the same time last year when mosquitoes had not yet become a problem. By the end of June, however, following a series of downpours, the bugs were back.
That triggered a decision to begin residential fogging, causing an uproar in Wolseley, where many residents are opposed to pesticides.
However, Gadawski said the city has substantial new resources to battle the plague this year, including:
One extra helicopter, raising the fleet to four. As well, the choppers are available for a longer period of time than they were last year.
Better information. Gadawski said the department has a more detailed understanding of the location of mosquito breeding sites than it did in past years.
An additional 30 seasonal staff have been hired, raising the total to 200.
A new bylaw allows insect fighters to enter private property to apply larvicide, if necessary.
Gadawski said the city will be able to handle normal or above-normal rainfall, but sustained wet weather, combined with hot, humid conditions, could overwhelm the department.
Spray crews, he said, have launched a fourth round of larviciding by air, truck and ground staff in the south side of the city, where the bulk of standing water has accumulated.
Crews continue to find moderate to high levels of mosquito eggs.
"We have four helicopters involved in about 70 per cent of larviciding. We have nearly 200 seasonal staff on the ground and we have a better understanding of where the standing water is," Gadawski said. "So far, we've been successful. We've been busy, but not overwhelmed."
Crews testing pools of water for nuisance mosquito larvae haven't yet discovered any culex tarsalis, the more rare breed thought to transmit the West Nile virus.
Gadawski does, however, believe the breed is out there in miniscule numbers, primarily in permanent and semi-permanent standing water. He said city crews will take direct aim at those sites, using the same insecticides that work on nuisance mosquitoes.
"Anywhere you see an area with cat-tails, that's an area of preference," he said. "The breed has a very high mortality rate through the winter, though some do survive. Locating (the larvae) is like finding a needle in a haystack."
Culex tarsalis also breeds in containers that can hold even a small amount of water, and Gadawski again urged home owners to dump all containers that may be a haven for the species.
Gadawski said if the larvae is controlled early, the chance of the virus spreading to birds and, ultimately, to people, is dramatically reduced.
"Early intervention is the key against this species," he said, adding the culex tarsalis can breed even during dry times, as long as permanent water is present. "They lay their eggs directly on the water surface, and they hatch almost immediately. This year, we expect there could be three generations of the species."
That's why even during the drier months of July and August when nuisance mosquitoes aren't an issue, the city will continue to larvicide for culex tarsalis.
Meanwhile, on the cankerworm front, the city's spraying program is into its third week, and the majority of trouble neighbourhoods have been completed.
Gadawski said some scattered areas with trees stripped by the caterpillars will now be targeted.
Republished from the Winnipeg Free Press print edition June 11, 2003 $sourceSection$sourcePage
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