The dung rolling scarab beetles

Dung beetles are beetles that feed partly or exclusively on feces. Hluhluwe-Umfolozi Game Reserve, South Africa. (Photo Bjorn Grotting)

Two dung beetles doing what they do best. Many dung beetles, known as rollers, are known for rolling dung into spherical balls, used as food or egg chamber. Hluhluwe-Umfolozi Game Reserve, South Africa. (Photo Bjorn Grotting)

Now, what is it NOT to love about dung beetles? Actually I can’t think of anything. Take for example the fact that most of the about 5.000 subspecies feed partly or exclusively on feces. Why don’t they ever consider another diet, you may ask? But that is exactly the recipe for their success. Remember Darwin never said “survival of the strongest”, he said “survival of the fittest”. The most adaptable species will succeed, and dung beetles have definitively found their niche.

So what’s so great about an insect that consumes and bury manure? Most people never think about it, but what happens if tons of dung from livestock are left alone on the fields is that it becomes a habitat for pests like flies. Another benefit is the improved recycling of nutrients and improvement of the soil structure. The cattle industry in the United States alone estimates a saving of several hundred million US$ every year due to the actions of the dung beetles. No wonder then that countries like Australia and New Zealand have introduced certain species of dung beetle. The quality and fertility of the pastures, as well as hygiene, has since improved considerably.

The ancient Egyptians regarded several species of the dung beetle as sacred. The best known is the Scarabaeus sacer (the sacred scarab). The Egyptians believed the dung beetles was purely of male gender and deposited their semen into a dung ball. This resembles Khepri, the god of the rising sun, who created himself out of nothing. The dung ball also symbolizes the sun.

In fact both male and female will be around the ball, but usually it is the male that rolls while the female is hitch-hiking. This is no big deal for a dung beetle which can roll up to 50 times it’s own weight. The ball is then buried in soft soil, and the female will lay her eggs inside it. When hatched the larvae will feed on the dung surrounding it.

Dung beetles with this behavior is known as “rollers”, like those you can see on the image above. Other subspecies are known as “tunnelers”, which bury the dung at the same spot as they find it. Another group is called “dwellers”, who simply live in the manure without any rolling nor burrowing.

As I said, what is it not to love about them?

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