Dung beetlemania
A Whenuapai firm aims to revolutionise New Zealand agriculture by breeding an army of underground critters to clean up manure and turn it into a positive.
Dung beetles are extremely inconsiderate of the summer holidays. During the sunny months, when the country shuts down, summer-season dung beetles are hard at work at Dung Beetle Innovations (DBI). The firm’s 3ha (7.5 acre) breeding shed in Whenuapai, west of Auckland, teems with critters.
The problem is rural couriers services are closed at this time of year, which means the beetles can’t be shipped to their future homes. To prevent them from flying away, Dr Shaun Forgie, an entomologist and DBI’s co-founder, has to get the beetles to chill out in industrial fridges until after the holidays.
“This is just one of the challenges of working with a living organism. The beetles can be a handful, but unlike children, they aren’t picky about what they eat, as long as it's livestock manure.”
Dung beetles dine on the manure of all grazing animals, including cows, sheep, alpacas, and horses. Adult beetles then create tunnels under the manure, filling them with balls of dung. In the middle of each ball, they lay an egg.
In most parts of the world, dung beetle species have a symbiotic relationship with livestock, but not in NZ. Native dung beetles are adapted to a forest environment and aren't much help cleaning up manure.
“We've brought livestock to this country without dung beetles that have evolved to process their manure," says Shaun. "It's a broken ecological system where we have stock without the natural clean-up crew."
DBI's eight species of dung beetle are native to southern Africa, the Mediterranean, and south-west Europe, including southern England. Their feeding habits mean pasture is sustainably enriched without fertiliser. The different species are active at different times of year, and burrow to different depths.
By removing manure from the ground surface, this underground army is also a solution to New Zealand's water pollution problems. One recently published study saw an 80 percent reduction in the run-off of contaminants on pastures colonised with dung beetles.
“I believe dung beetles can fix many of this country's problems and will be more effective than riparian planting schemes in stemming the surface flow of contaminants entering our waterways,” says Shaun.
Dung beetles can also improve land use, helping to reduce dung-breeding flies, and parasitic worms.
Some research suggests dung beetles could also reduce the production of methane and nitrous oxide in fresh manure, although more studies are needed to quantify the benefits.
Establishing dung beetles in NZ began in 2009 with iwi consultation and an application to ERMA (now the Environmental Protection Authority). The five-year compliance process included risk analysis, cost and benefits analysis, the presentation of hundreds of published studies, and several trials to ensure that dung beetles wouldn't be invasive or adversely affect New Zealand's ecology. Shaun says it was a long, and at times, infuriating process.
But in 2011, DBI received the necessary permission to introduce 11 types of dung beetle. In 2014, it set up the world's largest commercial breeding facility. It currently sells about 600 beetle colonies per year.
The Greater Wellington Regional Council has subsidised the cost of buying dung beetles for farmers in its area. More than 200 colonies have been established on 49 farms, 20 percent of farms in the catchment. This large-scale colonisation will also help the region improve its freshwater quality, and act as a case study for other parts of New Zealand.
This year, DBI will introduce two more approved species of dung beetles that are most active in spring. It's also involved with a large-scale colonisation project at the Whangawehi catchment in Mahia. This is funded by Beef + Lamb's Regenerating Hill Country project and Meat & Livestock Australia, which will compare the results with findings across the Tasman.
How to clean up your pasture
Dung Beetle Innovations sells colonies of dung beetles to help farmers improve soil health, pasture quality, and reduce run-off. It sells several different species of dung beetles suited to different rainfall levels and seasons.
DBI recommends that block owners work together as a group to buy a package of beetles. Beetles don't respect property boundaries and having a larger area with more stock will increase the chances and speed of establishment.
"There's a risk of the beetles not establishing or flying to a neighbour's farm. Form a consortium with like-minded neighbours." Couriers deliver beetles in containers. Beetles are released onto fresh dung piles, and will eventually go on to colonise a paddock. Colonies can expand up to a kilometre per year.
In mild, northern climates, it can take 2-3 years before you see signs of beetle activity, and 9-11 years for them to be at full
• carrying capacity.