The choices for chemical insecticides and yard sprays abounds. As a mother and pet owner, almost every yard spray or long-term yard chemical treatment offered at my local stores made me too uncomfortable to even test. We did try short-term sprays meant to keep the yard clear for a few hours, but even those made us uncomfortable. The impact on my family members aside, there are environmental concerns about these pesticides affecting other animals (notably frogs and birds). I do have to report that a RAID yard fogger, for instance, that we sprayed in mosquito friendly shrubs did seem to work very well for an afternoon. Read all directions and follow them carefully. Use sparingly.
There are, of course, less caustic sprays. We couldn't resist trying out the Mosquito Barrier brand of yard spray, which is supposed to repel mosquitoes for several weeks. The Barrier is highly concentrated liquid garlic. (Insert your own joke here about using garlic to repel bloodsuckers!) Laughing the entire time, we sprayed a mosquito-filled yard, following directions. It was fairly easy to do, and took less time than we thought. As parents we were relieved about the lack of toxic effects on our pets and children. Neighbors started to ask why they hadn't been invited to our spaghetti dinner, because the smell of garlic was indeed very strong, but the scent was gone in about an hour. Though we laughed as we sprayed, we also admit that we noticed a difference for several days. Like everything else, it was best used in combination with other products, but there didn't seem to be much of a downside in using this as an alternative to nastier chemical sprays. The Mosquito Barrier can be washed away by strong rains, and in some climates, daily thunderstorms are not uncommon, so frequent spraying would be necessary.