Saturday, January 24, 2009

Dun Rollin

Dung beetle attacks millipede

A scarab species has been filmed in Peru attacking and eating millipedes 10 times its length.

D. valgum or the Dung Beetle is no longer dining just on feces. Instead, the nocturnal creature prefers to decapitate live prey with its armour "teeth" and then devour their insides.

It is a rare example of a scavenger species turning carnivore, say US scientists in a Royal Society journal.

Dung beetles (Scarabaeidae) are not renowned for their predatory instincts. They feast on

fresh animal feces which they gather into balls and roll with their hind legs.

But after the species Deltochilum valgum was seen grappling with millipedes several times its size, Dr Trond Larsen of Princeton University decided to find out whether it could actually be preying on the creatures.

"This is a remarkable transition," wrote Dr Larsen, a tropical ecologist, in the journal Biology Letters.
"Despite its close relationships with dung feeding species, D. valgum has entirely abandoned its ball-rolling behaviour, it shows there is only so much crap you can take.
"This is the first known case of an obligate predatory dung beetle species."

The carnivorous beetles use the same mouthparts their cousins use to extract bacteria from dung and carrion as weapons to assault and kill their much larger prey.

When placed together in observation chambers, the beetles began their attacks by grasping a millipede's body with its mid- and hind-legs.
The millipedes - up to 110mm long - responded by coiling or flailing their bodies to resist the grip of beetles just 7-8mm wide.

After waiting until the flailing slowed down, the beetles inserted their armour teeth between body segments, prying upwards with their head while simultaneously sawing with their fore-teeth.

"During one kill we observed, the force of the beetle's prying severed the millipede's head from the rest of its body," said Dr Larsen.

The team say their discovery demonstrates how small changes in the physiology of a species can lead to giant leaps in its behaviour.

If they were 4 foot tall they would rule the world.

The scientists believe this unusual evolutionary transition from a scavenger to a hunter-predator was driven by high levels of competition for food and the use of steroids in cattle that gets passed on to the beetles thus making them more aggressive ........ like Americans.

Dung beetles have been found to be fussy eaters. In 2006, researchers in Kuwait found when offered dung from horse, camel and sheep the beetles preferred the more fluid horse dung to the others I mean who wouldn't?

African dung beetle was the first animal found to navigate using moonlight, enabling it to orientate itself and make a hasty retreat from competitors when rolling a ball of dung.

So what will be next ? we asked Dr Larsen: "Probably Dung Beetle bloggers".

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