Menus Subscribe Search

Follow us


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

November 21 • 4:00 PM

Why Are America’s Poorest Toddlers Being Over-Prescribed ADHD Drugs?

Against all medical guidelines, children who are two and three years old are getting diagnosed with ADHD and treated with Adderall and other stimulants. It may be shocking, but it’s perfectly legal.



November 21 • 2:00 PM

The Best Moms Let Mess Happen

That’s the message of a Bounty commercial that reminds this sociologist of Sharon Hays’ work on “the ideology of intensive motherhood.”


November 21 • 12:00 PM

Eating Disorders Are Not Just for Women

Men, like women, are affected by our cultural preoccupation with thinness. And refusing to recognize that only makes things worse.


November 21 • 10:00 AM

Queens of the South

Inside Asheville, North Carolina’s 7th annual Miss Gay Latina pageant.


November 21 • 9:12 AM

‘Shirtstorm’ and Sexism in Science

Following the recent T-shirt controversy, it’s clear that sexism in science persists. But the forces driving the gender gap are still being debated.


November 21 • 8:00 AM

What Makes a Film Successful in 2014?

Domestic box office earnings are no longer a reliable metric.



November 21 • 6:00 AM

What Makes a City Unhappy?

According to the National Bureau of Economic Research, Dana McMahan splits time between two of the country’s unhappiest cities. She set out to explore the causes of the happiness deficits.


November 21 • 5:04 AM

Sufferers of Social Anxiety Disorder, Your Friends Like You

The first study of friends’ perceptions suggest they know something’s off with their pals but like them just the same.


November 21 • 4:00 AM

In 2001 Study, Black Celebrities Judged Harshly in Rape Cases

When accused of rape, black celebrities were viewed more negatively than non-celebrities. The opposite was true of whites.


November 20 • 4:00 PM

Women, Kink, and Sex Addiction: It’s Not Like the Movies

The popular view is that if a woman is into BDSM she’s probably a sex addict, and vice versa. In fact, most kinky women are perfectly happy—and possibly healthier than their vanilla counterparts.


November 20 • 2:00 PM

A Majority of Middle-Class Black Children Will Be Poorer as Adults

The disturbing findings of a new study.


November 20 • 12:00 PM

Standing Up for My Group by Kicking Yours

Members of a minority ethnic group are less likely to express support for gay equality if they believe their own group suffers from discrimination.


November 20 • 10:00 AM

For Juvenile Records, It’s ‘Justice by Geography’

A new study finds an inconsistent patchwork of policies across states for how juvenile records are sealed and expunged.


November 20 • 8:00 AM

Surviving the Secret Childhood Trauma of a Parent’s Drug Addiction

As a young girl, Alana Levinson struggled with the shame of her father’s substance abuse. But when she looked more deeply into the research on children of drug-addicted parents, she realized society’s “conspiracy of silence” was keeping her—and possibly millions of others—from adequately dealing with the experience.



November 20 • 6:00 AM

Extreme Weather, Caused by Climate Change, Is Here. Can Nike Prepare You?

Following the approach we often see from companies marketing products before big storms, Nike focuses on climate change science in the promotion of its latest line of base-layer apparel. Is it a sign that more Americans are taking climate change seriously? Don’t get your hopes up.


November 20 • 5:00 AM

How Old Brains Learn New Tricks

A new study shows that the neural plasticity needed for learning doesn’t vanish as we age—it just moves.


November 20 • 4:00 AM

The FBI’s Dangerous Misrepresentation of Encryption Law

The FBI no more deserves a direct line to your data than it deserves to intercept your mail at the post office. But it doesn’t want you to know that.


November 20 • 2:00 AM

Brain Drain Is Economic Development

It may be hard to see unless you shift your focus from places to people, but both destination and source can benefit from “brain drain.”


November 19 • 9:00 PM

Gays Rights Are Great, but Ixnay on the PDAs

New research suggests both heterosexuals and gay men are uncomfortable with public same-sex kissing.


November 19 • 4:00 PM

The Red Cross’ Own Employees Doubt the Charity’s Ethics

Survey results obtained by ProPublica also show a crisis of trust in the charity’s senior leadership.



November 19 • 2:00 PM

Egg Freezing Isn’t the Feminist Issue You Think It Is

New benefits being offered by Apple and Facebook probably aren’t about discouraging women from becoming mothers at a “natural” age.


Follow us


Sufferers of Social Anxiety Disorder, Your Friends Like You

The first study of friends' perceptions suggest they know something's off with their pals but like them just the same.

Standing Up for My Group by Kicking Yours

Members of a minority ethnic group are less likely to express support for gay equality if they believe their own group suffers from discrimination.

How Old Brains Learn New Tricks

A new study shows that the neural plasticity needed for learning doesn't vanish as we age—it just moves.

Ethnic Diversity Deflates Market Bubbles

But it's not in the rainbow and sing-along way you'd hope for. We just don't trust outsiders' judgments.

Online Brain Exercises Are Probably Useless

Even under the guidance of a specialist trainer, computer-based brain exercises have only modest benefits, a new analysis shows.

The Big One

One company, Comcast, will control up to 40 percent of Internet service coverage in the U.S., and 19 of the top 20 cable markets, if a proposed merger with Time Warner Cable is approved by regulators. November/December 2014

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