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Whatsapp Dung beetles are formidable engineers.

Don't turn your nose up at them! Dung beetles are colourful, hard-working and keep flies away from your barbeque. Ann Jones gets up close and personal with the underdogs of pasture ecosystems.

Hundreds of soil engineers are pressing material into tunnels barely wider than their shoulders—digging, shifting, rolling and fertilising a pasture.

As they're going along, they're doing you a favour. The more they dig, the fewer flies will be at your next barbeque.

These engineers work in cow pats all across Australia, moving the fibres around and crushing fly larvae as they go.

They are dung beetles, introduced to Australia as a part of a long-running biological control project administered by the CSIRO.

This is what their construction work sounds like:

The sound you can hear, a bit like rain, is the inside of a dung beetle-filled cow pat.

Though they spend much of their time with their heads buried in manure, dung beetles are fascinatingly complex and actually quite beautiful.

Vast areas of the Australian continent have been cleared for grazing since European settlement, altering local ecosystems substantially.

Areas that may have once been woodlands are now full of introduced species, including the cows themselves and the grasses upon which they feed.

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Whatsapp This dung beetle is known as Geotrupes spiniger.

There are native Australian dung beetles—approximately 350 known species of them—but they are generally specialist marsupial dung eaters. (That is, they prefer their poo to be small and pelletised, rather than a huge and moist.)

The lack of dung beetles acting on cow manure was a major problem for many reasons.

Each of Australia's 28 million or so cows produces about 12 cow pats a day, each a three litre mix of semi-digested grass.

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Whatsapp Onthophagus australis is a native Australian dung beetle.

Each of these pats is capable of producing 3,000 flies in the two weeks before it dries out completely. When you do the sums, that means the birth of a trillion flies from every day's harvest of cow pats.

Maybe this shouldn't be a surprise: the omnipresence of flies in Australia is part of our vernacular and folklore, after all.

There's the 'Aussie Salute'—the insistent swipe of the hand in front of the face—and the iconic swagman's hat with corks hanging off the brim to keep the blowies away.

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Whatsapp A dung beetle by the name of Onitis aygulus

Flies go for our faces and the moist, exposed parts of animals because they are after protein.

'They need protein from the animal secretions—the females do—to mature their eggs,' says Dr Jane Wright, a former CSIRO scientist and co-author of the recently re-released Introduced Dung Beetles in Australia: A Pocket Field guide.

'Some research showed that when flies develop in poor quality dung, they come out very small and they're very hungry.

'Whereas [with] a big fly, the female already has enough nutrients to actually produce a few eggs.

'Little flies have to eat and eat and eat, and they are the peskiest, because they're the ones who are most desperate to get protein to develop eggs.'

So these pesky insects swarm, seeking reproductive success by mining animal secretions for food.

'They irritate the animals unbelievably,' says Wright, speaking specifically about buffalo flies which bite the cows. 'Those animals are so busy trying to get rid of the blood feeders that they're not eating, and it really makes a difference to the productivity of the herd.'

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Whatsapp Dr Jane Wright is the author of A field guide to Australian Dung Beetles.

Enter the dung beetle project, run by the CSIRO and funded by Meat and Livestock Australia over various decades and iterations.

Interestingly, when the project first started in the 1960s, its focus was on controlling dung rather than flies.

'It was all about burying dung and getting it off the surface of the paddock because when it sits on top it smothers the grass. The grass that grows around it is rank—the cattle don't like it.'

Pretty quickly, scientists realised that they could, in fact, have it all when it comes to dung management—provided they matched the introduced species of dung beetles to the correct climatic conditions in Australia. Species from Europe, Africa and the Middle East are now established on Australian cattle farms.

Dung beetles not only out-compete fly larvae by disturbing their gestation within the dung, but also aerate pastures. The beetles bury ready-made fertiliser into the ground and free up the surface for the best pasture growth possible.

Happily—but unusually, as far as the introduction of foreign species goes—the scientists don't have to worry about any downsides.

'There are none!' Jane Wright laughs.

Hear the full story Dung beetles are the unlikely heroes of both biological control and Australian barbecues. Seriously.

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