Foreign dung beetles to improve local soil

A shipment of foreign dung beetles has arrived in Australia with the purpose of improving pasture productivity in the southeast.

After being captured in Morocco last month, the 1500 beetles are now tasked with breeding new generations that will improve local soils by breaking down their favourite meal.

Thousands of their eggs will be harvested and sent to a mass rearing site at Charles Sturt University’s campus in Wagga Wagga, NSW.

There, a further two generations will be produced before the dung beetle is released onto Australian farms, within the next two years.

Dung beetles act as biocontrol agents by burying and eating dung, keeping the soil healthy and helping to kill flies and other pests.

CSIRO researcher and project leader Valerie Caron said the latest importation includes a new species called G. sturmi.

“It’s a really long trip, and I’m always impressed that they survive,” an excited Dr Caron said of the new imports.

The new species went through a rigorous risk assessment to check that they wouldn’t pose a threat to any other animals when introduced, including native dung beetles.

“The risk assessment is looking at everything that is known about a species and then making the decision if it’s safe or not to bring in,” she said.

“For those species they only eat cattle and sheep dung, and there was no negative impact.”

The captured beetles were first sent to a CSIRO laboratory in France where they were cleaned and fed, then starved before being shipped to Australia.

Biosecurity laws mean only the dung beetle’s offspring can leave the CSIRO facility, while their ancestors will continue breeding in captivity.

“We don’t quite play nice music and put candles on, but we have the best conditions possible for them to make babies,” Dr Caron told AAP.

Moroccan beetles are chosen partly because of climate similarities with southern Australia.

While Australia has more than 500 native dung beetle species, 23 non-native species also help process the dung of imported animals.

“We brought all the livestock (into Australia) but there were no dung beetles that could get the dung from the surface and put the dung in the soil,” says Dr Caron.

The dung beetle ecosystem engineers project is a joint venture between industry group Meat and Livestock Australia, the federal science agency CSIRO, several universities and landcare groups.

This latest arrival is the last import of beetles for the project, which has been running for five years.

In December 2021, two-thirds of a group of dung beetles died while trapped in transit for a month, after the courier company suffered a COVID-19 outbreak.

However, such losses are rare and all of the latest batch survived the journey.

Charles Sturt University professor Leslie Weston is now gearing up to receive “the valuable commodity”.

Her job is to take the beetles outdoors for the first time.

“We increase their numbers through a mass rearing effort, and we keep them well fed and under sanitary conditions in large walk-in growth chambers,” Prof Weston said.

“We’re hopeful that this rolling beetle will continue to successfully roll dung into balls and incorporate it ... into the soil, thereby limiting pests, in particular flies.”