Better Border Biosecurity (B3) members are celebrating the official announcement of two pest eradications in December 2015, with a third successful eradication hopefully to be announced this year. B3 has worked collaboratively with MPI and other agencies to help successfully eradicate Queensland fruit fly (Qfly) from Grey Lynn and the Eucalyptus leaf beetle from Upper Hutt. The great white butterfly has not been detected for 15 months in the Nelson Tasman region and official eradication will hopefully be confirmed this year.

Queensland fruit fly

The February 2015 discovery of several Qfly in Grey Lynn, Auckland represents the most significant fruit fly incursion in New Zealand since 1996. This was the fourth Qfly detection in the last three years, but the first case of a population actually establishing in New Zealand.

MPI responded immediately with their science-based response and eradication protocols, and B3 researchers were among the experienced team that promptly set out to help eradicate the small population. B3 assisted MPI by supporting MPI’s decision-making through modelling of Qfly phenology, overwintering ability, trap sensitivity, spring mating behaviour and proof-of-freedom monitoring times.

B3 members have also worked to better understand the risks of fruit flies in New Zealand, including research on population ecology and surveillance. Research has progressed on self-reporting traps and B3 partner Plant & Food Research is working with the international consortium SITplus to develop and trial new lures for early detection of Qfly (see previous story - New Zealand Contributes to Fruit Fly Research). Research continues into the feasibility of multi-species lures (previously co-funded by MPI).

B3 also helped MPI understand when, under international standards, they could make the announcement that New Zealand was Qfly free. The Controlled Area was lifted at 2pm on 4 December 2015, and there are no longer any restrictions on the movement of fresh fruit and vegetables in Auckland.

Eucalyptus leaf beetle

The second recent eradication was of another Australian native, the Eucalyptus leaf beetle, from Whiteman’s Valley in the Upper Hutt. The beetle, which feeds on Eucalyptus species, was first detected in a stand of trees in late 2012. The eradication response reflected the combined expertise of many contributors, including MPI and B3.

B3 researchers supported the eradication programme in a number of ways. First, the innovative spot spraying methods that achieved minimal drift are the outcome of a history of research by Scion and B3. These techniques were the key to success in this semi–urban environment.

Second, the sampling protocols for delimitation and to indicate the insect is no longer present were developed through B3 research. B3 designed MPI’s survey of surrounding areas that showed the beetles had not spread from the small site where they were originally detected.

The restricted semi­rural site and support from local land­owners meant that this infestation could be treated with targeted helicopter sprays, the first eradication to use aerial spraying since painted apple moth.

Great white butterfly

 A third eradication campaign that B3 has recently contributed to is the great white butterfly (GWB), which has not been detected in the Nelson Tasman region since December 2014, despite ongoing intensive surveillance. There is real hope that it has been eradicated, thanks to the DOC-led programme that began in 2012 with support from Vegetables NZ, Horticulture NZ, Tasman District Council, Foundation for Arable Research, Dairy NZ, MPI and the TR Ellet Agricultural Research Trust.

B3 has provided considerable scientific support to the GWB eradication programme ever since the pest was first discovered in Nelson in 2010, including estimating detection efficacies of passive and active surveillance, modelling spatial extent and population trends, identifyng  hot spots, phenology modelling to predict seasonality, refining search and response strategies,  measuring the attractiveness of butterfly lures, population genetics, and parasitoid augmentation. 

It is almost certain that the project will conclude this year if no further GWB are found. The eradication team is conducting another round of surveillance across the Nelson Tasman region this summer and autumn to confirm eradication.

For more information contact: 

 David Teulon (B3 Director)

david [dot] teulon [at] plantandfood [dot] co [dot] nz