Insect’s million dollar appetite

A tiny insect no larger than a 10 cent coin is saving New Zealand dairy farmers millions of dollars each year.

A new Landcare Research quantitative study shows the ragwort flea beetle, and its huge appetite, is saving dairy farmers $44m in costs to control the invasive pest plant from which it takes its name.


A new Landcare Research study has found the ragwort flea beetle is saving New Zealand dairy farmers $44 million in pest plant control. Photo: Landcare Research

It's believed Kiwi dairy farmers spend $20m per year to control ragwort, a weed which invades pastoral land and is toxic to cattle and horses.

Landcare scientist Simon Fowler says up until now they've only been able to speculate on the financial benefits of the flea beetle to farmers.

'We had no hard data, we had amazing before and after photos of the flea beetle's work but people need quantitative data,” he explains.

'So we revisited our research and have now finished a national cost-benefit analysis.”

For his research Simon used data taken from a study conducted on the West Coast where the flea beetle failed to thrive due to the wet climate back in 2005. He took the amount of money farmers spent killing the weed and then extrapolated the total across New Zealand's dairy sector.

Though his methodology also factored in inflation and national dairy herd size, he says the end figure still took everyone by surprise.

'It will be the first published post-release weed biocontrol agent economic analysis for New Zealand and we think it shows in a very tangible way how smart science can assist the primary sector.”

To date the flea beetle has wiped out ragwort on 50 per cent of New Zealand farms.

But the weed remains a problem on about a quarter with many farms located in wet regions in the West Coast, Taranaki and Northland region.

A second insect, a plume moth that thrives in wet conditions, is being deployed to tackle remaining ragwort strongholds and looks set to reduce the threat of ragwort further.

The flea beetle had actually been shortlisted as a potential control agent during the 1930s but was dismissed – a decision Simon's calculated to have cost farmers a staggering $8 billion.

'That's how much farmers spent on controlling ragwort up until 1983, when the Department of Scientific and Industrial Research imported and released the flea beetle.”

While biocontrol agents are not always as successful, the flea beetle is truly a 'success story”.

He says farmers can 'get on a continual treadmill of spraying herbicides to control the weed” but that only provides temporary relief and doesn't give the flea beetle a chance.

It takes a bit of nerve but sometimes they need to take a deep big breath and do nothing, advises Simon.

'The $44 million saving is ongoing and free, and we can be confident that this little golden beetle will not do anything other than munch through this particular weed.

'Be patient and let the ragwort flea beetle do the work for you,” says Simon.

To learn how to help the flea beetle flourish on your farm visit Landcare Research's website at: http://bit.ly/1QHdrP5.

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1 comment

So.......

Posted on 19-02-2016 18:41 | By Jimmy Ehu

This all sounds wonderful, but can Simon please tell me what happens to the hungry flea, when there is no ragwort left? .


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