This can be very tricky. Normally, these annoying little critters remain holed up in their respective, dank holes and their buzzing and flapping is ignored by the busy citizens of this valley. Fortunately their buzzing and flapping can be heard a mile away. In case some of you are new to the Santa Clarita Valley, I'm going to give you a few handy hints that will give you a slight edge in the upcoming event. Don't worry that this is unsportsmanlike.
Gadflies never play by the rules and are innately bad-tempered.
The ultimate goal of this Running of the Gadflies is control of Santa Clarita's water supply. All gadflies suffer from myopic delusions of grandeur and their Napoleonic complexes prevent them from seeing any farther than the stingers on the ends of their, er, heinies. They want to teach developers a lesson by keeping water from the citizens of the Santa Clarita Valley. I would suggest Raid Flying Insect Zapper. With this spray, there is no need for a direct hit because the fumes can penetrate beneath rocks, a favorite gadfly hangout.