University News for June 12, 2012

An entomologist with the University of Manitoba warns recent heavy rains can be expected to result in another flush of biting mosquitoes.

Although reduced run-off from snowfall this past winter combined with limited rainfall this spring have resulted in low populations of mosquitoes so far this season, increased amounts of rain have helped reverse the situation.

Dr. Terry Galloway, an entomology professor with the University of Manitoba's Faculty of Agricultural and Food Sciences, says a group of mosquitoes sometimes called floodwater mosquitoes are very well adapted to Manitoba conditions.

Clip-Dr. Terry Galloway-University of Manitoba:
The floodwater mosquitoes mostly are the ones that are responsible for the severe annoyance.

They're very persistent biters.

They're really well adapted to prairie conditions where you have periodic droughts and periods of higher rainfall and some of our most serious pests are in this group.

What happens is their eggs can sit on the sides of ditches and low-lying areas for years in fact.

That's why they can get through long periods of prairie drought and then when we get heavy rainfall, the summer kinds of thundershowers where we get several inches of rain all at once and those ditches fill up.

As the water rises in the ditches and the eggs are submerged they hatch and they produce a generation of mosquitoes.

With the conditions that we've had in the last couple of weeks, the warm weather last week, the really high temperatures that we had during the week, that means that any mosquitoes that were developing these pools grow even faster.

Although it's cooled down now a little bit, we're getting another bout of rainfall and that may elevate the levels of the pools, we may even get more mosquitoes hatching again after that rainfall over the weekend.

Dr. Galloway notes, while these species of mosquitoes are not considered to be a major vector for the spread of pathogens, they are out in enormous numbers and are a severe annoyance.

For UniversityNews.Org, I'm Bruce Cochrane.

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