It depends on the species of horsefly. Some species are quite small under 1/2". The largest horsefly in North America is the Tabanus atratus or Giant Horsefly. They are often over 1.5" and it isn't uncommon to find them over 2". http://images.whatsthatbug.com/images/black_horsefly_ruler.jpg Has a picture of a Giant Horsefly that is slightly over 2".
About the size of a 10 year olds thumb.
keeps the bugs away like big flies
I wish they did. No, they like blood. They're like really big, hungry mosquitos.
There are horse flies in Virginia, same as there are horse flies almost everywhere else in the world. There are specifically more horse flies in the east coast, especially in Florida. As for Virginia there's nothing special about the horse fly population there. Just the same old horse flies like everywhere.
Horse flies don't like water because if they went in water it would kill them and horse flies prefer blood.
Pteronarcophobia is the fear of flies, which includes horseflies.
Frogs
Yes, there are all sorts of flies everywhere in the world. Horse flies are in Florida. :)
If the horse fly is carrying a disease it can.
Horse flies exist because they evolved from a common insect ancestor with other flies. They fill a certain niche in the ecosystem.
Well, the horse's shadow would be as big as the horse at certain times of the day...
Horse flies fly using wings, just like any other kind of fly.
A horse fly has approximately 6 legs on their body. Horse flies are larger than other species of flies.