Everything you need to know about dung
beetles
Dung beetles are a relatively modern group of beetles, their fossils only extend
back to 40 million years ago.
There are about 7 000 species world wide.
Dung beetles range from less than 1mm to a giant 6cm.
Dung beetles occur on every continent except Antarctica.
The life expectancy for most dung beetles range from three to five years.
A researcher observed that a small 1.5 Kg pile of Elephant dung on the African
savannah attracted 16 000 dung beetles of various shapes and sizes, who between
them had eaten and or buried that dung completely in just two hours. One dung
beetle can bury 250 times its own weight in a night.
Most of the dung beetles in the world use herbivore dung, though many are not
very particular and will use many different forms of dung,
Some species have definite preferences for one type of dung only.
Onthophagus caenobita has only ever been found feeding in human faeces.
A dung beetle in South America called Zonocopris gibbicolis feeds on the faeces
of large snails on whom it rides around.
The female dung beetle lays a single egg into each ball of dung and then covers
the nest with more dung and soil. When the eggs hatch, the larvae will feed on
the fecal matter.
Dung beetles can be divided into 3 groups, Rollers, Tunnellers and Dwellers.
Rollers are species who make a burrow some way away from the dung they are going
to use and then collect small to medium sized lumps of dung to roll into their
burrows. Typhaeus typhoeus, the Minotaur Beetle, can dig burrows up to one metre
deep. Generally the female does most of the digging and the male spends most of
his time collecting the dung for her. Rollers dig their front legs into the
ground and use their back legs to push the ball of dung.
Tunnellers fly until they find some fecal matter into which they dive. They dig
a tunnel and then drag as much dung as they like down into it. Again it is
mostly the female who stays in the burrow sorting out the dung and the male who
goes out to get it.
Some dung beetles eat and lay their eggs on dung some other beetle has
collected. The thief often eats the legitimate dung-owners eggs as well as
stealing their dung.
The females of many of the larger 'Rollers' stay inside their burrows and care
for and protect their eggs and young, these species can live for up to 3 years.
Some of these larger dung beetles can move balls of dung up to 50 times their
own weight.
Australia imported 45 species of dung beetle from various parts of the world to
get rid of cattle dung.
In ancient Egypt the scarab or dung beetle was the most important religious
symbol. In some Indian tribes from South America a dung beetle named Aksak is
supposed to have modelled the first man and woman from clay.
Without dung beetles, the earth would be piled high with manure.
http://www.earthlife.net/insects/dung.html
Reproduction
The rollers establish a pair bond. They usually meet in the dung pat. The male
offers the female a giant-sized brood ball which if accepted, they roll away
together, or with the female riding on the ball. During this time, other beetles
often attempt to steel the ball. They find a soft place and bury the ball before
mating - mostly underground. The male then leaves to find further partners. The
female of this species makes a brood 'pear' or 'pears' and lays a single egg in
each. She then coats the pear with an antiseptic mixture of dung, saliva and
faeces to seal it in a case which hardens solid. Unusual in insects, this
species exhibits the highest level of parental care seen in an insect. She stays
with the ball and her grub for two months, cleaning it and removing its faeces,
fungi and bacteria.
Dung Beetles
How do dung beetles (Scarabaeus zambesianus) maximize their chance to get the
most out of the available dung? Get it away from competitors. New research
suggests this beetle can use polarized moonlight at night to navigate the way as
it rolls a dung ball to a safe spot away from the pile. Observers watched
beetles foraging on moonlit nights and cloudy or moonless nights. With a moon,
the beetles rolled their dung balls away in a straight line. This is the most
efficient path. Without a moon, the beetles could not roll the ball in a
straight line. Further, to differentiate between influence of the moon itself
and moonlight’s polarization pattern, a large polarizing filter was placed over
the beetles. When adjusted by 90 degrees, this caused the beetles’ course to be
changed by 90 degrees. Researchers concluded it was not the moon itself, but the
polarization pattern that guided the dung beetle. It is known that many
creatures use the polarization pattern of sunlight for navigation, but this
believed to be the first time the use of moonlight polarization patterns has
been documented. –Nature Brief Communications, July 3, 2003.