Redback spider research

Dr Craig Phillips (left) and Dr Cor Vink holding a jar containing a redback spider

Lincoln-based AgResearch scientists Dr Cor Vink and Dr Craig Phillips published some startling findings on redback spiders recently in the international journal ‘Biological Invasions’.

While MAF and scientists were already aware the pest is established in Central Otago and New Plymouth, the comprehensive review and analysis shows
that redbacks can establish in many other parts of New Zealand, particularly urban areas around major ports.

Dr Vink recorded sightings, and modelled the biological and climatic information of redback spiders, and Dr Phillips overlaid this with habitat data to reveal where
redbacks could establish. Dr Phillips also spent much of a summer holiday studying the spiders in Central Otago.

“We knew that warm dry conditions, such as those in some eastern areas of New Zealand, are suitable for redbacks, but we’ve now found that they can spread further than we expected. We know now that, where there is shelter from high levels of rainfall such as in urban areas, they can prosper.

Dr Vink says that redbacks are an issue for New Zealand. “In Otago redbacksare feeding on an endangered species of chafer beetle and there is also genetic evidence that redbacks have interbred with protected katipo near Gisborne and could displace them.”

While redbacks are a public health risk, they aren’t aggressive, and advice is that if you see one it should be trapped and MAF contacted.

Long-term biosecurity measures are vital to protect New Zealand, and AgResearch works alongside border protection agencies to assess risk and recommend ways to minimise incursions. Funded by the Foundation for Research, Science and Technology as part of Better Border Biosecurity, the programme is a large multi-partner 12-year science initiative.