Check out the feature section for stories on mayflies and midges. There you'll see why they're an important part of the local ecosystem and why they should not be controlled, even if they could.
That said, mosquitoes are not that big of a concern at Cedar Point, as they have few areas to breed (according to my fiancee biologist who wrote those "bug" articles). They breed in stagnant water, and Cedar Point makes it a point to avoid standing water, thus the fountains in the lagoons on the Power Tower midway and around Iron Dragon and Mantis. The parts that don't have fountains are regularly "stirred" by the passing Paddlewheel Excursion boats. Other areas that have water, like the water rides and such, have constantly moving water.
The only place I can think of that would make good places to breed mosquitoes are in puddles on the roofs of buildings, but even then they'd have to be in the shade at all times or they'd get baked by the sun.
I'm not saying that there are no mosquitoes in the park, but their presence isn't that significant.
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Jeff
Webmaster/Guide to The Point
"And he says 'I'm goin' crazy up there at the lake...'"