Robber flies are interesting insects. Fierce predators that snatch prey in mid-air or steal booty from other predators. It is a beneficial insect in that it hunts common agricultural pests but it's not your friend. Bites from these beasties are quite painful. They don't go out of their way to do this but threaten one and a nasty welt is often the repercussion. This female fly has mistaken the steel cable as a suitable place to deposit her eggs.