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


Introduced insects not such a pest

Introduced insects not such a pest

Lincoln, New Zealand 14 January 2014... Concerns are often raised about the introduction of non-native insects around the world to control weeds, citing the risk the introduced insects may cause to other desirable plant species. Yet a new study suggests there may not be as much evidence for this concern as people perceive.

An international collaboration - including Max Suckling of Plant & Food Research in Lincoln, New Zealand and René Sforza of the European Biological Control Laboratory in Montpellier, France - has completed a study on the effects of all recorded cases since the 1800s of insects as weed biological control agents thanks to funding from an OECD Fellowship and as part of NZ’s Government funded Better Border Biosecurity programme ( ).

The research characterised the magnitude of unwanted effects by these insects on other plants using a five step scale adapted from invasive species biology and looked at 512 cases of deliberately introduced biocontrols dating back more than 150 years.

Dr Suckling said “A total of 43 weed biocontrol insects worldwide have been reported to feed on non-target plants after release, but the real surprise comes when you look at the level of this feeding and what little effect it is having on the plants, compared with calls for concern about biosafety in the scientific literature”.

The study particularly looked at whether insect feeding affected the reproductive rate of the non-target plant and discovered decreases in plant reproduction in non-target plants to be very rare.
The scientists found only four insects causing plant populations to decline significantly anywhere.

“Weeds are a major long term drain to our quality of life. Our concern is that worry about biosafety needs to be tempered with the benefit scenario. Our analysis shows that as far as is known, weed biological control agents have historical had an excellent biosafety track record, with more than 99% of cases avoiding significant non-target impacts on plant populations” says Dr Suckling.

“Biological control of weeds through the introduction of specific insects is an environmentally sustainable solution compared to chemical sprays and an area of science we aim to investigate further” notes Dr Sforza, currently visiting New Zealand on an OECD Fellowship for biological control.

The study estimates that in the nearly 85 year history of weed biological control in New Zealand, 34 % of insects deliberately introduced against weeds have worked successfully, in some cases with real benefits. Two key success stories have occurred from insects introduced to control St John’s Wort and Ragwort, with long-term ecosystem recovery over large areas.

The study notes that in future it is expected that even fewer non-target impacts and greater benefits can be expected due to improved science and increased incorporation of wider societal values and that suitably-screened organisms can be released with a very high degree of specificity against weeds. The research paper is available online in PLoS ONE (10.1371/journal.pone.0084847).

View the research paper online
PLoS ONE – article by Suckling and Sforza,
What magnitude are observed non-target impacts from weed biocontrol? (
10.1371/journal.pone.0084847 (


© Scoop Media

Business Headlines | Sci-Tech Headlines


Welcome Home: Record High Migration Stokes 41-Year High Population Growth

New Zealand annual net migration hit a new high in October as more people arrived from than departed for Australia for the first time in more than 20 years. More>>


Citizens' Advice Bureau: Report Shows Desperate Housing Situation Throughout NZ

CAB's in-depth analysis of over 2000 client enquiries about emergency accommodation shows vulnerable families, pregnant women and children living in cars and garages, even after seeking assistance from the Ministry of Social Development and Housing New Zealand. More>>


Speaking For The Bees: Greens Call For Neonicotinoid Pesticide Ban

The National Government should ban the use of controversial pesticides called neonicotinoids after evidence has revealed that even at low doses they cause harm to bee populations, the Green Party said today. More>>


Science Awards: NZAS Celebrate NZ Scientific Achievements

The Marsden Medal is awarded for a lifetime of outstanding service to the cause or profession of science, in recognition of service rendered to the cause or profession of science in the widest connotation of the phrase. This year’s medal is awarded to Dr Mike Andrews. More>>


Court Rules: Affco 'Unlawfully' Locked Out Meat Workers

The note says the full court found for the plaintiffs, "that is that the defendant locked out the second plaintiffs unlawfully and that it breached s 32 of the Act by acting otherwise than in good faith towards the plaintiffs while collective bargaining was still going on." More>>


Get More From Scoop

Search Scoop  
Powered by Vodafone
NZ independent news