Video | Business Headlines | Internet | Science | Scientific Ethics | Technology | Search


Mighty moths flown in to ravage ragwort

Mighty moths flown in to ravage ragwort

PHOTO CAPTION: Anything but boring: This crown boring moth has arrived in New Zealand with an important mission - to destroy the noxious pasture pest, ragwort. PHOTO: Hugh Gourlay

New troops have arrived to wage war on one of New Zealand's worst weeds, and are undergoing safety checks before being deemed battle-worthy.Ragwort (Senecio jacobaea) replaces pasture, and can cause fatal liver damage if eaten by cattle and horses.

Biological control agents including the ragwort flea beetle have been released nationwide to attack ragwort plants. But although these have destroyed significant amounts of ragwort (up to 100% in some cases), they have failed to make a real indent on the West Coast, where overall, the problem is as bad now as it was 20 years ago. Landcare Research has been leading the charge to find alternative biocontrol agents, better suited to the wet conditions of areas like the West Coast.

Landcare Research weed researcher Hugh Gourlay says that with ERMA (Environmental Risk Management Authority) approval, about 350 ragwort crown boring moths (Cochylis atricapitana) have just arrived in New Zealand. The moths were placed in containment upon arrival, and over the next 18 months will undergo testing to determine whether they will eat anything other than ragwort.The crown boring moths will be joined next month by the ragwort plume moth (Platyptilia isodactylus).

The plume moths will also be kept in containment and undergo the same tests. Mr Gourlay says the moths are of European origin, but have been sourced from Tasmania, where they both have successfully established in the wild. "The two moths are better adapted to wet soils and wet climates than the ragwort flea beetle.

Some areas of Tasmania have a wet climate similar to the West Coast, and a similar ragwort problem.

"The crown boring moths have had good results there. Ragwort plants attacked by them produce fewer seeds, and show reduced growth and flowering. In some cases, the moth kills the entire plant.

"The plume moth attacks the roots of ragwort plants. It is too early to tell the plume moth's overall impact in Tasmania, but early results look promising.

"Neither moth has eaten any plant besides ragwort, which is also an encouraging sign."

Mr Gourlay says the new arrivals are the first new agents for the biocontrol of ragwort since 1981 when the ragwort flea beetle was introduced.Subject to approval from ERMA, the moths will be released into the West Coast environment by the end of 2005.

Several other places of similar climate throughout New Zealand may benefit from the introduction of these moths, including Southland and Waikato.

The project to import the moths was initiated by West Coast farmers and the New Zealand Landcare Trust, with funding from farmers, the Ministry of Agriculture and Forestry Sustainable Farming Fund, the West Coast Development Trust, the West Coast Regional Council, the Department of Conservation, Forest & Bird (West Coast branch) and Westland Milk Products.


© Scoop Media

Business Headlines | Sci-Tech Headlines


Science Investment Plan: Universities Welcome Statement

Universities New Zealand has welcomed the National Statement of Science Investment released by the Government today... this is a critical document as it sets out the Government’s ten-year strategic direction that will guide future investment in New Zealand’s science system. More>>


Scouring: Cavalier Merger Would Extract 'Monopoly Rents' - Godfrey Hirst

A merger of Cavalier Wool Holdings and New Zealand Wool Services International's two wool scouring operations would create a monopoly, says carpet maker Godfrey Hirst. The Commerce Commission on Friday released its second draft determination on the merger, maintaining its view that the public benefits would outweigh the loss of competition. More>>


Scoop Review Of Books: She Means Business

As Foreman says in her conclusion, this is a business book. It opens with a brief biographical section followed by a collection of interesting tips for entrepreneurs... More>>


Hourly Wage Gap Grows: Gender Pay Gap Still Fixed At Fourteen Percent

“The totally unchanged pay gap is a slap in the face for women, families and the economy,” says Coalition spokesperson, Angela McLeod. Even worse, Māori and Pacific women face an outrageous pay gap of 28% and 33% when compared with the pay packets of Pākehā men. More>>


Housing: English On Housing Affordability And The Economy

"Long lead times in the planning process tend to drive prices higher in the upswing of the housing cycle. And those lead times increase the risk that eight years later, when additional supply arrives, the demand shock that spurred the additional supply has reversed. The resulting excess supply could produce a price crash..." More>>


Sweet Health: Sugary Drinks Banned From Hospitals And Health Boards

All hospitals and DHBs are expected to kick sugary drinks out of their premises. University of Auckland researcher, Dr Gerhard Sundborn who also heads public health advocacy group “FIZZ”, says he welcomes the initiative. More>>


Get More From Scoop

Search Scoop  
Powered by Vodafone
NZ independent news