post peak mosquito season: "Are we there yet, are we there yet?"

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Chip Down
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post peak mosquito season: "Are we there yet, are we there yet?"

Post by Chip Down » July 29th, 2018, 7:43 pm

I've always thought of August as the worst month for mosquitoes, but I consistently hear others say July.

Christopher Ingraham (Washington Post) thought it would be enlightening to look at Google searches. He reasoned that, human nature being what it is, people don't plan ahead and develop a mosquito strategy in March. They wait until they want relief, and then start researching repellents and remedies. His analysis shows peak interest in June and July. August is lower than May. Ingraham acknowledges geographic variation by state, but of course as hikers we also care about how the peak at Indian Heaven might compare to the peak at Cairn Basin.

In your subjective personal opinion, when does mosquito activity taper off? (Of course, what really matters is when they're biting, but I've never seen swarms of docile mosquitoes.)

Also, are you aware of any data from field observations, as opposed to Ingraham's armchair study?

Aimless
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Re: post peak mosquito season: "Are we there yet, are we there yet?"

Post by Aimless » July 29th, 2018, 8:37 pm

In the Cascades and Wallowas my observation has been that mosquito number start to ramp up when the snow coverage is about 40% - 50% of the available ground. The numbers continue to increase until snow coverage is about 0% - 10%. Then they continue high for about two weeks following 0% snow coverage. After that, the rate of decrease is heavily dependent on hot weather. The hotter it is, the quicker the numbers go down.

This is, of course, subject to elevation. Lower elevations reach 0% sooner. High elevations later. It also depends on the presence or absence of shallow lakes or ponds in the area. Some areas abound in lakes and ponds, such as Indian Heaven, Sky Lakes wilderness, or the southern half of Three Sisters wilderness. Other areas, like the northern half of Three Sisters have few. High pond/lake incidence can keep mosquito numbers fairly high until the first hard frost arrives.

You need to know the locality, snow melt rate, and local weather over the past several weeks to predict where the mosquitos are worst.

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drm
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Re: post peak mosquito season: "Are we there yet, are we there yet?"

Post by drm » July 30th, 2018, 5:30 am

August is typically the peak month on our taller mountain alpine areas. But the snow melted very early this year and so that moved the season up almost a month. On Mt Adams the mosquitoes are well past peak on the south and west sides. I've heard that the north is still fairly bad but also should by now be just past peak. This very extended heat wave we are just about to finish should have dried up most of their puddles so the current generation will not be able to reproduce and the typical lifespan of a mosquito is weeks to a month. I don't think they use lakes so much, they need smaller puddles.

Aimless
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Re: post peak mosquito season: "Are we there yet, are we there yet?"

Post by Aimless » July 30th, 2018, 8:49 am

Lakes that support populations of trout are poor breeding grounds for mosquitos, because their larvae are eaten by the fish. This doesn't stop them from trying, because a mosquito has no way to tell a lake from a pond from a puddle. :D

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Re: post peak mosquito season: "Are we there yet, are we there yet?"

Post by drm » July 31st, 2018, 1:31 pm

Yes, hungry fish are a factor, so is temperature. A deeper lake that stays cold will not produce as many mosquitoes. A shallow lake warms faster and a tiny puddle can warm up in a day if in the sun.

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Re: post peak mosquito season: "Are we there yet, are we there yet?"

Post by Aimless » July 31st, 2018, 1:40 pm

I'm pretty sure water temp does play a big role, but the top six or eight inches of a deep lake are usually pretty warm, especially near the shallower edges. However, I readily admit I've never made a study of mosquito breeding habits in regard to their ability to discriminate between bodies of water. I do know I root for every bird, insect, fish or animal that makes mosquitos a big part of their diet! :D

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retired jerry
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Re: post peak mosquito season: "Are we there yet, are we there yet?"

Post by retired jerry » July 31st, 2018, 1:56 pm

When the snow melts it leaves lot of puddles and wet areas for mosquitoes

As they dry up, the biggest number of mosquitoes die off. Their mating is complete.

Continuing through the season, there will still be some wet areas so there'll be a smaller number of mosquitoes.

When there's a good freeze at night, that will kill off the mosquitoes so there will be few left.

That's my theory :)

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MarkInTheDark
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Re: post peak mosquito season: "Are we there yet, are we there yet?"

Post by MarkInTheDark » September 19th, 2018, 8:33 am

I was just up on Benson Plateau... no bugs!

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