In the study, scientists calibrated the males’ strength by gluing a cotton thread to the beetles’ hard wing-cases, stringing the thread across a pulley, and tying it to a miniature bucket, to which they added drops of water [ScienceNOW]. The dung beetle’s coronation as the world’s strongest insect steals the thunder from the rhinoceros beetle, which can lift up to 850 times its own weight.
Dung beetles developed this strength in other to compete for mates, but that isn't their only strategy. Some weaker male dung beetles mate successfully because they have “substantially bigger testicles”. Link
(image credit: Alex Wild)