At Jerrabomberra Wetlands in the middle of this wet summer, entomologist John Feehan delivered a presentation on dung beetles without having to brush away any bush flies.
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"For the first time in the history of Canberra out there in Jerrabomberra, there were 500 people 150 metres from 150 head of Angus cattle and there were no flies," Mr Feehan said.
"I did count one, in fact I tried to catch it to show people," he said.
Bush flies feed and breed in cow pats. One pat can produce 2000 bush flies. Mr Feehan, who distributes dung beetles around the country and abroad, says every one of Australia's 28 million cattle drops about 12 pats a day. But thanks to dung beetles burying dung in the Canberra region, bush flies have become a rarity.
In his early days with the CSIRO Mr Feehan worked alongside Dr George Bornemisza, a migrant who used his knowledge of dung beetles to convince the Australian government to import them to suppress bush flies.
"He spoke with a slight Hungarian accent, he used to say, 'Da bush flies, boys, are just a sideshow. It is da soil fertility issue dat's the big thing'," Mr Feehan said. Australia's fragile soils cannot produce enough food to sustain population growth without farmers importing large amounts of phosphate, from sources forecast to expire in three decades.
Yet half a million tonnes of dung containing phosphorous and nitrogen is dropped on the ground every day.
"The only trouble is when it sits on top of the ground it breeds bush fly and buffalo fly, and internal parasites complete their life cycle so more chemicals have to go inside the animal, which we end up with in residues," Mr Feehan said.
"The dung pollutes the paddocks and gets washed into the creeks and rivers," he said.
As a boy Mr Feehan would find any number of fist-sized green frogs holding onto reeds in the creeks around Braidwood. "Now, at Braidwood I can walk up those creeks that I walked along as a kid, not a frog. The reason they are not there is because of the wetting agents the farmers use on their crops, and all the rest that don't break down.
"Remember when frogs were slimy? Well the wetting agent in the herbicides and insecticides dissolves the slime on the frog and they die of UV, or something like that. That is just another of the nightmares."
When dung beetles bury the dung, they aerate the soil and restore nutrients in root zones.
"We have water catchment authorities all around Australia. If those people helped me put dung beetles into their water catchment areas, 80 per cent of them would lose their jobs," Mr Feehan said.
Foxes are suppressing the spread of some of the dung beetles in Canberra. Mr Feehan said in addition to the beetles the CSIRO released, he donated another five species, and foxes chomped on four of these species.
"Foxes are sitting beside fresh dung of an evening and just eat the big beetles, they grab them out of the air," he said. "In fact I shot a fox south of Cooma, cut it open and got 72 of those big blue beetles, one hour after sunset."
