How dung beetles will improve NZ's farms

  • 08/10/2013

Around 500 dung beetles have been released in the south Wairarapa as part of a plan to improve the soil on dairy farms.

This release will be the second to take place in New Zealand, after a Southland farm introduced dung beetles to its soil last month.

The big question is, what they will actually do for our ecosystem?

Bug expert Ruud Kleinpaste says the species being introduced into the North Island are "master diggers" that will return nutrients in cow manure right back into the soil where they fall.

"Nature knows no waste – whatever you and I may think of as waste, they think is a resource," he said on Firstline thismorning.

"So what they do is they dig it into the ground, they lay their eggs in it and their young will feed on it. They will break down the dung into food for plants again, for the pastures or whatever grows there. This is now nature deals with waste."

Prior to colonisation New Zealand had no large mammals like cows and sheep, so no bugs evolved to deal with the large amount of waste they produce.

Mr Kleinpaste says this is the case in many parts of the world, which is why the dung beetle, originally from southern Europe, has been such a hit.

"They've been actually spread quite much around the world because a lot of agronomists see the value in dung beetles – the poo doesn't lie on top of the grass for a long time, cattle can graze straight away, the nutrients are recycled back into the land… fewer flies, fewer parasitic things for the cattle. It's all very good for the environment."

But could they one day prove to be a pest, like other introduced species such as rabbits and stoats? Mr Kleinpaste doubts it.

"There is no way you're allowed to import anything into New Zealand without an enormous body of research," he says.

"I think they spent something like $600,000 [on] research, which tells everybody that these guys would be very beneficial and pose basically no threat at all to our ecological systems.

"As long as you don't have them in your mouth, you should be fine."

Experiments with dung beetles in New Zealand have so far proven to be a success.

The 500 beetles in Wairarapa are expected to start breeding in six to eight weeks, and could eventually supply the rest of the country.

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source: newshub archive