How do horseflies breed?

Here's a quote from a great Web site on tabanids (horseflies). "When the fly emerges from its pupal case females will seek a blood meal, whilst the males feed on nectar. The next priority for a newly emerged fly is to mate. This usually takes place during the early hours of the morning. Males come together in swarms above the forest canopy and females are attracted to these swarms. Females enter these dipteran "lekking" sites and copulation is initiated in the air, the act is completed on the ground and takes approximately five minutes." If you're interested, there's a lot more at this webiste: http://www.roberth.u-net.com/horseflies.htm#lifecycle