Menus Subscribe Search

New Zealand Imports Foreign Workers: Dung Beetles

• October 21, 2011 • 4:00 AM

Burned by past introductions of “helpful” foreign species, New Zealand inches toward releasing the imported insects to clean up its pastures full of other introduced animals.

New Zealand farmers Dean and Marjorie Blythen are poised for an unlikely spot in the history books — early next year their property, about 30 miles north of Auckland, will become home to the country’s first officially imported dung beetles.

In what will be the start of a nationwide rollout of the industrious little insects, Blythen expects his 200 Hereford cattle and between 500 and 600 sheep to be joined by perhaps 1,000 to 2,000 beetles at an initial release site on the farm.

Those beetles, among 11 species being imported from South Africa, Australia, France, and Spain, are currently in quarantine before an outdoor mass rearing program and release into the wild. The intentional introduction of an invasive species — sometimes dubbed an “exotic” when the result is benign — has generated some furor in a land where past invasives have trampled on native species.

Hugh Gourlay, senior researcher with Landcare Research, the environmental management company handling the beetles’ transition, says the species have been carefully selected to be the most active and effective in New Zealand conditions.

They have been matched to the variable climate, seasonal changes, temperatures and soils, and include a mix of day and night foragers. “The idea is that we’ll have dung beetles working 24/7 all round the year,” Gourlay says.

Which is just as well, as they have a mighty task ahead of them: cleaning up the poop left behind by New Zealand’s roughly 10 million beef and dairy cattle, themselves an introduced animal.

Gourlay says at any one time an estimated 5 percent of productive land — nearly two million acres — is not being grazed because it is soured by dung, which discourages cattle from feeding nearby.

In addition, he says, as these Frisbee-shaped piles of excrement begin to deteriorate they can contaminate waterways, provide a breeding ground for bacteria and flies, and contribute to global warming by emitting nitrous oxide.

While some dung beetles roll animal manure into balls and then bury it, the New Zealand varieties tunnel. They will live under the cow pats, pushing the dung down into tunnels where beetle grubs will feed off the nutrient-rich contents.

Gourlay says the beetles can remove a pile of cow manure in as little as 24 to 48 hours, burying it anywhere between four and 20 inches underground.

Beyond the broad environmental benefits, Blythen likes what he calls the health spin-offs. “If they bury the dung, in the process they should take the eggs of internal parasites down below their ability to hatch and come back to the surface again.”

The beetles also offer farmers another tangible bonus: saving money on fertilizer by protecting grass quality, aerating the pasture, and using the nutrients and nitrogen stored in dung to enrich the soil.

The overall economic benefits are hard to quantify, but a 2006 study published by the American Institute of Biological Sciences concluded that dung beetles were worth about $380 million annually to U.S. cattle farmers.

The introduction of any new species is always a touchy subject in New Zealand. Its native wildlife has suffered terribly as a result of the innocent — though in retrospect often reckless — import of unsuitable animals since European settlement in the first half of the 19th century.

For example, in the early days of the then-British colony, rabbits were happily ushered ashore, only to repay the hospitality by breeding profusely, stripping vast areas of pasture and undermining farmland with their burrows.

In a bid to control the rabbits, stoats, ferrets, weasels and even domestic cats were released into the wild, setting free a scourge of nature’s most efficient killers in an environment containing some of nature’s most defenseless wildlife.

More recent accidental imports, like the Argentine ant, now advancing steadily down the country’s North Island, and the German wasp, illustrate the disproportionally negative impact that even small insects can have.

The Environmental Risk Management Authority, the government agency controlling the introduction of new animals, plants and other organisms, gave dung beetles the go-ahead only after more than two years of investigation, reports, and public submissions.

As might be expected with New Zealand’s sobering track record, the proposal sparked lively debate and some controversy.

Submissions to the authority raised questions about possible conflict with the country’s 15 species of native dung beetle, which evolved at a time when New Zealand was covered in forest and still feed primarily on leaf litter.

Concern was also expressed about interaction with earthworms. Others objectors believed the beetles might spread animal diseases and some questioned their effectiveness in reducing parasitic reinfection rates.

Opposition to the introduction was partially muted by reference to the beetles’ benign impact in their native countries and the experience of Australia, which has imported more than 40 species since 1968.

Having neighboring Australia acting almost like a laboratory has been very helpful, says Andrew Barber, manager for the Dung Beetle Release Strategy Group, which represents farmers and other industry stakeholders. “We’ve ridden a little bit on their coattails,” he admits.

Meanwhile, Gourlay concedes that some of the issues raised by objectors cannot be answered without “20 years of intensive research” but on all the evidence available he remains confident and optimistic.

“We’ve struggled to find downsides,” he says, pointing to what he sees as the positive experiences of Australia, Hawaii and the U. S. mainland. “They all have had really good experiences and great results from introducing dung beetles.”

Still, some critics remain unconvinced and are left wondering if New Zealanders will look back in 20, 50 or 100 years and add dung beetles to the list of pests they should have seen coming.

Sign up for the free Miller-McCune.com e-newsletter.

“Like” Miller-McCune on Facebook.

Follow Miller-McCune on Twitter.

Add Miller-McCune.com news to your site.

Subscribe to Miller-McCune

Frank Nelson
Frank Nelson has written for newspapers and magazines in England (his original home), New Zealand (his adopted home), Australia (a temporary home) and the United States (his current home). The author of two lighthearted travel books, All You Need is Luck and A Little More Luck, he is now a freelance writer based in Santa Barbara, Calif.

More From Frank Nelson

A weekly roundup of the best of Pacific Standard and PSmag.com, delivered straight to your inbox.

Recent Posts

July 29 • 2:00 PM

Under Water: The EPA’s Ongoing Struggle to Combat Pollution

Frustration and inaction color efforts to enforce the Clean Water Act.


July 29 • 12:40 PM

America’s Streams Are Awash With Pesticides Banned in Europe

You may have never heard of clothianidin, but it’s probably in your local river.


July 29 • 12:00 PM

Mining Your Genetic Data for Profit: The Dark Side of Biobanking

One woman’s personal story raises deep questions about the stark limits of current controls in a nascent industry at the very edge of the frontier of humans and technology.


July 29 • 11:23 AM

Where Should You Go to College?


July 29 • 10:29 AM

How Textbooks Have Changed the Face of War

War is more personal, less glorious, and more hellish in modern textbooks than in the past. But there’s still room for improvement.


July 29 • 10:00 AM

The Monolingual American: Why Are Those Outside of the U.S. Encouraging It?

If you are an American trying to learn German in a large German town or city, you will mostly hear English in return, even when you give sprechen your best shot.


July 29 • 8:00 AM

The Elusive Link Between Casinos and Crime

With a study of the impact of Philadelphia’s SugarHouse Casino, a heated debate gets fresh ammunition.


July 29 • 6:00 AM

What Are the Benefits of Locking Yourself in a Tank and Floating in Room-Temperature Saltwater?

After three sessions in an isolation tank, the answer’s still not quite clear.


July 29 • 4:00 AM

Harry Potter and the Battle Against Bigotry

Kids who identify with the hero of J.K. Rowling’s popular fantasy novels hold more open-minded attitudes toward immigrants and gays.


July 29 • 2:00 AM

Geographic Scale and Talent Migration: Washington, D.C.’s New Silver Line

Around the country, suburbs are fighting with the urban core over jobs and employees.


July 28 • 4:00 PM

Border Fences Make Unequal Neighbors and Enforce Social Inequality

What would it look like if you combined Israel, the West Bank, and Gaza, demographically speaking? What about the United States and Guatemala?


July 28 • 2:00 PM

Are Patient Privacy Laws Being Misused to Protect Medical Centers?

A 1996 law known as HIPAA has been cited to scold a mom taking a picture of her son in a hospital, to keep information away from police investigating a possible rape at a nursing home, and to threaten VA whistleblowers.


July 28 • 12:00 PM

Does Internet Addiction Excuse the Death of an Infant?

In Love Child, documentary filmmaker Valerie Veatch explores how virtual worlds encourage us to erase the boundary between digital and real, no matter the consequences.


July 28 • 11:11 AM

NASA Could Build Entire Spacecrafts in Space Using 3-D Printers

This year NASA will experiment with 3-D printing small objects in space. That could mark the beginning of a gravity-free manufacturing revolution.


July 28 • 10:00 AM

Hell Isn’t for Real

You may have seen pictures of the massive crater in Siberia. It unfortunately—or fortunately—does not lead to the netherworld.


July 28 • 8:00 AM

Why Isn’t Obama More Popular?

It takes a while for people to notice that things are going well, particularly when they’ve been bad for so long.


July 28 • 7:45 AM

The Most Popular Ways to Share Good and Bad Personal News

Researchers rank the popularity of all of the different methods we have for telling people about our lives, from Facebook to face-to-face.


July 28 • 6:00 AM

Hams Without Ends and Cats Tied to Trees: How We Create Traditions With Dubious Origins

Does it really matter if the reason for why you give money to newlyweds is based on a skewed version of a story your parents once told you?


July 28 • 4:00 AM

A Belief in ‘Oneness’ Is Equated With Pro-Environment Behavior

New research finds a link between concern for the environment and belief in the concept of universal interconnectedness.


July 25 • 4:00 PM

Flying Blind: The View From 30,000 Feet Puts Everything in Perspective

Next time you find yourself in an airplane, consider keeping your phone turned off and the window open.


July 25 • 2:00 PM

Trophy Scarves: Race, Gender, and the Woman-as-Prop Trope

Social inequality unapologetically laid bare.


July 25 • 1:51 PM

Confusing Population Change With Migration

A lot of population change is baked into a region from migration that happened decades ago.


July 25 • 1:37 PM

Do Not Tell Your Kids That Eating Vegetables Will Make Them Stronger

Instead, hand them over in silence. Or, market them as the most delicious snack known to mankind.



July 25 • 11:07 AM

The West’s Groundwater Is Being Sucked Dry

Scientists were stunned to discover just how much groundwater has been lost from beneath the Colorado River over the past 10 years.


Follow us


Subscribe Now

America’s Streams Are Awash With Pesticides Banned in Europe

You may have never heard of clothianidin, but it's probably in your local river.

How Textbooks Have Changed the Face of War

War is more personal, less glorious, and more hellish in modern textbooks than in the past. But there’s still room for improvement.

NASA Could Build Entire Spacecrafts in Space Using 3-D Printers

This year NASA will experiment with 3-D printing small objects in space. That could mark the beginning of a gravity-free manufacturing revolution.

The Most Popular Ways to Share Good and Bad Personal News

Researchers rank the popularity of all of the different methods we have for telling people about our lives, from Facebook to face-to-face.

Do Not Tell Your Kids That Eating Vegetables Will Make Them Stronger

Instead, hand them over in silence. Or, market them as the most delicious snack known to mankind.

The Big One

One in two full-time American fast-food workers' families are enrolled in public assistance programs, at a cost of $7 billion per year. July/August 2014

Copyright © 2014 by Pacific Standard and The Miller-McCune Center for Research, Media, and Public Policy. All Rights Reserved.