How many stages are in a horse flies life?

The adult horse fly's life span is around 30 to 60 days, however, the total life cycle may take a lot longer. Most species of horse fly spent the entire winter in a larval state and pupate during spring and early summer. They then lay eggs from late summer to early autumn and the process starts again. The entire life cycle normally take around a year, although some of the larger species can live for two to three years.