Armies of dung beetles could one day become a familiar sight on Wairarapa farms, thanks to teams from Greater Wellington Regional Council [GWRC] and Dung Beetle Innovations [DBI].
During the summer of 2019, about 50 local farmers put their hands up to co-fund dung beetle packages designed to encourage on-farm trials, leading to cleaner pasture and environmental and economic benefits.
Currently, 60 per cent of Wairarapa dairy farms and 40 per cent of sheep and beef farms have invested in dung beetles.
The excrement-loving beetles work to bury livestock dung, which aerates the soil, improves the nutrient cycle, and helps manage water absorption and dispersion.
According to the DBI website, when properly established the beetles’ environmental and economic benefits will start to be noticed after four to six years.
Meanwhile, farmers can expect to see beetle activity in three to four years and full carrying capacity reached in nine to 10 years.
Entomologist and DBI co-founder Dr Shaun Forgie said over 900 farms in New Zealand use dung beetles, with a 94 per cent success rate.
Auckland-based DBI currently imports 11 species of dung beetles into the country to ensure dung removal is efficient all year round, day and night, and across a variety of soil types.
“The only way you can kill them off is by getting rid of your stock or by basically over-managing it,” Forgie said.
“There’s 100 million tonnes of cow and sheep excrement produced each year – that’s our estimate. To put it into a visual sense, that’s putting an Olympic pool, head to tail, from Cape Reinga to Bluff filled with cow and sheep poo each year.”
GW environment restoration advisor Kolja Schaller said that although there are early signs of beetle establishment in Wairarapa, it’s still early days.
“It’s good that we’ve got some signs they’re establishing, but whether or not they will take off across the whole region, only time will tell,” Schaller said.
During an annual monitoring process held in February of this year, teams from GWRC and DBI found evidence of dung beetle establishment on four farms located from Carterton to Pirinoa.
The species that was found on a farm near Pirinoa was the Onthophagus binodis.
Beetles were found in traps on a sheep and beef block, and beetle larvae were seen inside dung balls that are burrowed underneath dung pat.
“There’s evidence in other places of New Zealand that show they’re going really well, with multiple different species establishing – so there’s no real reason why it shouldn’t here,” Schaller said.
“We’re introducing a handful of beetles, anywhere between 200 to 500 individual beetles of one species at a site, where they start to get into the dung, burying the dung, and colonising the area.”
The dung beetle package includes four different species of beetles – each of which has enough beetles to form individual colonies.
“I think people are waiting until they start seeing signs of establishment, and potentially, we’ll get another wave of people getting on board once they see that it’s working.”
As a part of its mitigation toolkit, GWRC is offering 50 per cent off its dung beetle packages; if you’re interested, get in touch via phone 0800 496 734 or email: [email protected]