A new species of Moroccan beetle has just arrived in our lab. Their job? To improve pasture quality and reduce fly populations. We’re expecting big things from these little creatures.
When introduced species of dung beetles first arrived in Australia as biological control agents they certainly had their work cut out for them.
The ecological damage caused by the arrival of cows and sheep with the First Fleet in 1788 was 200 years in the making. Pastures were in ruin and the native bush fly was flourishing in sloppy, wet cow dung.
Back in the 1970s, our scientist George Bornemissza was the first person to put the biological link back in the chain. He brought in the first introduced dung beetle species as biological control agents.
The dung beetles’ legacy continues
Fast forward to June 2021 and a new shipment of Moroccan dung beetles (Gymnopleurus sturmi) has arrived on Australian shores.
A long way from home in northern Africa, we’re hoping the beetle will thrive in southern Australia as the climatic conditions are similar to those in Morocco.
There are 5000 species of dung beetles worldwide and Australia is home to 500 native species. Our native beetles evolved with kangaroos, wallabies and wombats. So, while they’ve picked up some skills in breaking down marsupial dung, the sloppy dung left behind by cows and sheep is no match for our local beetles.
A beetle for all seasons
Our entomologist, Dr Valerie Caron, is responsible for bringing in the new batch of beetles. “To date, 45 species have already been introduced, of which 23 have established. We’re in the process of introducing three new species,” Valerie said.
“Even though dung beetles have done a fabulous job in Australia, gaps in activity still exist. Currently, we don’t have beetles who work through spring in Southern Australia, and we need beetles working so we don’t have dung accumulating during these months,” she said.
Rolling on in
The new batch of Moroccan beetles are known as “Rollers”. They’ve acquired their name due to their nature of rolling and burying a ball of dung. Not only do the beetles lay one egg in each dung ball, but they also use dung as a food supply for adults and larvae.
And believe-it-or-not, this is our first roller rodeo (in recent times).
“This is the first time in recent years that we’ve brought in Rollers. This species aggregate and trample the dung making it impossible for flies to lay eggs,” Valerie said.
“Dung beetles aren’t just good at controlling flies. Burying dung makes nutrients available to plant roots, aerates the soil and reduces water runoff and nutrient loss. Other related benefits include fewer livestock parasites and a reduction in carbon emissions.”
We observe Australia’s strict biosecurity measures when bringing in any biological agent.
Before arriving in Australia, researchers study the beetles in the field before taking them to our lab in Montpellier, France, for biosecurity processing. Researchers then clean them and remove any mites. Once the beetles have the all-clear, they are set for travel to our lab in Canberra.
Only adult beetles are allowed in to quarantine. The adults are reared for eggs and all eggs are surface sterilised for 15 minutes then rinsed before exiting quarantine.
After quarantine, our partners in the Dung Beetle Ecosystem Engineers program rear the beetles in mass-rearing facilities for a few generations. After this, we can release adults into the field.
Where to from here
The beetles are very sensitive and will only establish when the conditions are well suited to them. While it could take up to five years to truly understand if our new Moroccan beetles thrive in Australia, our scientists are expecting big benefits from these little beetles.