Black Horse Fly

Large black (male) tabanid resting on a shed near my home. Adult male horse flies are identifiable by lack of eye spacing (note the lack of separation of this horsefly's compound eyes). Horseflies can have up to 30,000 ommatidia (tiny units) per compound eye!

Another interesting tidbit: Male horseflies are not aggressive blood feeders (like females). They feed primarily on nectar and pollen. Females are blood-feeding in order to acquire protein for egg production.