AUGUST
1988

 

 

 

By
Tom Turpin
 
Professor of
Entomology
Purdue University

 

 

 

 

 

8-25-88

WASTE DISPOSAL EXPERTS

The ancient Egyptians worshiped them as a god.  Barefoot farm boys in denim overalls have admired them for decades.  Scientists have studied them.  My teenage daughter thinks they're gross!

They are popularly known as dung beetles, tumble beetles, or tumble bugs.  Technically know as scarab beetles, these insects feed on manure.  Not any old manure, mind you, but mammal droppings left in pasture areas.  They are specialists in cow-pie disposal procedures.

Mated pairs of tumble beetles dig burrows in the soil, a home for their prospective offspring.  Following construction, the tumble beetles begin to provision the home.  The food chosen is mammal excrement, frequently cow manure.  Once a cow-pie – the fresher the better – is discovered, the beetles must package the food.  They make it into a ball – a very convenient shape for transporting – and roll the food home.

It is this habit of rolling the dung ball that gives the insects their common names.  Normally, one beetle pushes the ball with its hind feet while its mate pulls while walking backwards.  This procedure results in uncertain progress at best.  The journey is punctuated with frequent falls and tumbles.  But where there's a will, there's a way, and the two dedicated travelers usually make it home.

Once the manure ball is safely in the underground home, the female lays eggs on it.  The young larvae hatch and begin to feed on the manure and possibly the fungus that grows there.  Dedicated mother that she is, the female beetle frequently remains in the burrow t tend to the brood.

It was the ball-rolling habit of the tumblebugs that no doubt attracted the attention of the ancient Egyptians.  In fact, the scarab became the most popular insect in Egypt.  The scarab beetle common in Egypt has five terminal segments on each of its six legs.  To the ancient Egyptians, this symbolized the 30 days of each month.

The ancient Egyptians adopted the scarab as the symbol for their sun god, Khepera.  It is said that they believed that the beetle rolling the dung ball across the earth symbolized Khepera rolling the sun across the sky.  Because the sun was “reborn” each day, the beetle became the symbol of rebirth and was associated with the idea of the soul.

Scarab beetles were frequently put in tombs in an effort to ensure the immortality of the soul of the departed.   Nearly 3,000 years later, Roman soldiers adorned necklaces with a scarab form and wore them into battle.  This tradition was apparently based on the same idea of immortality that had been accepted by the Egyptians.  Necklaces with the scarab design can still be found today.

Dung beetles serve a very practical function, in ancient times and today, that of keeping our pastures free of animal manure.  The Australians learned this when large mammals were introduced to their country.  You see, Australian dung beetles had not adapted to dealing with manure other than that of the kangaroo, so the Australians had a problem piling up.  They solved it by importing “foreign” dung beetles.

Maybe the ancient Egyptians were correct.   If dung beetles aren't magical, they are surely essential!

 

Writer: Tom Turpin
Editor: Olivia Maddox