Post by Rick (Admin) on Jul 2, 2013 22:38:50 GMT -5
Shadflies are back in North Bay
Shadflies don't like the cold water.
The below-seasonal water temperature in Lake Nipissing has delayed their annual arrival, according to Jean-Marc Filion.
Filion, a local biologist, has been studying Lake Nipissing and Trout Lake for more than a decade. He said the shadfly arrival normally takes place in June.
“It's still cool for water activities,” Filion said. “They're looking for warmth. The kids don't even spend a lot of time in the water yet.”
The shadflies, which some people refer to as mayflies, is an annual insect ritual North Bay residents are used to seeing, hearing and smelling.
The visitors often catch tourists by surprise.
For about 21 days, the winged, mouthless insects emerge from Lake Nipissing and cover light poles and sidewalks.
According to Science North, nymphs will spend up to a year underwater before they emerge as an adult. The nymph will crawl out of the water by clinging on to a plant.
“It will then split its skin (called an exoskeleton) and a winged adult will emerge and take flight. The role of adult mayflies is to mate and lay eggs before they die.”
Their lack of mouths usually means their life-cycle usually lasts about a day.
Filion said there's no doubt there are changes happening in Lake Nipissing's ecosystem.
He said it's hard to pinpoint one thing that would result in a drop in shadfly numbers.
“Looking at the stomachs of walleye and yellow perch there were hardly any nymphs,” Filion said.
This year's shadfly season doesn't compare to what North Bay residents saw years ago.
“When I was a kid we would shovel them off like they were snow,” Filion said. “Now they're just a shadow of that.”
Filion said last year's hot weather in early spring and this year's cool temperatures isn't helping the production of shadflies.
“When things are climatized, animals have a hard time adjusting,” he said.
“We have blackflies in July. Things are definitely changing.”
Shadflies don't like the cold water.
The below-seasonal water temperature in Lake Nipissing has delayed their annual arrival, according to Jean-Marc Filion.
Filion, a local biologist, has been studying Lake Nipissing and Trout Lake for more than a decade. He said the shadfly arrival normally takes place in June.
“It's still cool for water activities,” Filion said. “They're looking for warmth. The kids don't even spend a lot of time in the water yet.”
The shadflies, which some people refer to as mayflies, is an annual insect ritual North Bay residents are used to seeing, hearing and smelling.
The visitors often catch tourists by surprise.
For about 21 days, the winged, mouthless insects emerge from Lake Nipissing and cover light poles and sidewalks.
According to Science North, nymphs will spend up to a year underwater before they emerge as an adult. The nymph will crawl out of the water by clinging on to a plant.
“It will then split its skin (called an exoskeleton) and a winged adult will emerge and take flight. The role of adult mayflies is to mate and lay eggs before they die.”
Their lack of mouths usually means their life-cycle usually lasts about a day.
Filion said there's no doubt there are changes happening in Lake Nipissing's ecosystem.
He said it's hard to pinpoint one thing that would result in a drop in shadfly numbers.
“Looking at the stomachs of walleye and yellow perch there were hardly any nymphs,” Filion said.
This year's shadfly season doesn't compare to what North Bay residents saw years ago.
“When I was a kid we would shovel them off like they were snow,” Filion said. “Now they're just a shadow of that.”
Filion said last year's hot weather in early spring and this year's cool temperatures isn't helping the production of shadflies.
“When things are climatized, animals have a hard time adjusting,” he said.
“We have blackflies in July. Things are definitely changing.”