This is a story about the $7.4 billion Australian cattle industry, cow manure, annoying bush flies and dung beetles.
And how they’re are all linked and why it’s important to clean up cow pats.
There are 28.5 million head of cattle in Australia each producing an average 12 dung pads a day. That’s 342 million each day.
And if we assume each cow produces between 20 kg and 30 kgs of dung each day, depending on the size of the animal and local conditions, then we have between 570 million and 855 million kilograms of manure created in Australia every day.
That’s as much 855,000 tonnes a day, or almost twice as much as the iron ore shipped from the port of Dampier in the North West each day.
And yes, the dung is spread across Australia and isn’t in one place to be loaded on to ships.
However, this mountain of dung causes two problems.
The first is that cows won’t graze near cow pats again, for couple of years sometimes. And it doesn’t take them long to fill a field. This reduces the amount of productive land by 3% a year, according to some estimates.
An the second is that a single cow pat can be the incubator of up to 3,000 bush flies in a fortnight.
The flies are also annoying, preferring to stick to human faces when they can, and impact tourism areas across southern Australia, including the south west wine region which, in the late 1960s and early 1970s was notorious for bush flies.
Dung beetles were introduced from Europe, Africa and Hawaii in the 1960s to clean up the cow pats which they did with amazing efficiency.
The dung beetles like to eat the cow pats and lay eggs there. They also are fascinating to watch as they collect piles of dung many times their size.
As the cow pats disappeared, the flies went as well.
This helped with the tourist industry, extended the productive grazing area and improved the soil.
A new species of dung beetle will be released in Kojonup, an inland town south of Perth, this week to tackle bush fly numbers.
It’s seen as a finishing-the-job exercise.
The Spring-active beetle Onthophagus vacca, an insect of French origin, will be released at sites around Kojonup.
The beetles were imported into Australia from France and Spain by CSIRO as part of a Meat and Livestock Australia-funded dung beetle project across southern Australia.
Department of Agriculture and Food Executive Director Terry Hill says the survey looked at existing populations of dung beetles across 12 sites in WA, and identified where significant impacts on bush fly numbers could be made by introducing the new species.
“Sites have been chosen where there are numerous large herds of cattle, therefore a large quantity of cow dung,” Mr Hill says.
“Releasing the beetle in these areas will maximise the opportunity for them to establish and hopefully spread.”
CSIRO researcher Jane Wright said a breeding colony has been established in a laboratory in Canberra.
The original beetles were placed in quarantine and the eggs from these were surface-sterilised following Australia Quarantine Inspection Service protocols and then released from quarantine and transferred to artificial brood balls.
“Over the last two years, we have developed a rearing technique that has allowed us to produce sufficient beetles for field releases,” Dr Wright says.
By introducing the spring active beetle, the long term goal is to stop fly numbers from building up over spring, allowing existing beetles to have a greater impact on fly populations over summer.
The beetles also improve soil fertility which will aid in better pasture production for livestock and reduce the nutrient runoff from dung into waterways.
Earlier this year established winter-active dung beetle Copris hispanus was collected from Williams near Kojonup and redistributed in the Geraldton and Badgingarra areas to tackle bush fly numbers.
You can see the new dung beetles here.
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