Date: 07 November 2013 Source: Joint release from Landcare Research, Victoria University and the Department of Conservation
Control measures and more funding are needed to stop the havoc being wreaked on New Zealand’s native forests by wasps, say scientists who hosted a workshop held recently at Victoria University.
“The target is well defined—summer wasp densities need to be reduced by 80 to 90 percent of current levels,” says Professor Phil Lester from Victoria’s School of Biological Sciences.
“Over the last few years, scientists have been hamstrung by a lack of wasp control technologies appropriate to New Zealand conditions.”
A Wasp Tactical Group established at the workshop welcomes participation from organisations counting the cost of wasps. Its goal is to develop a pathway to a New Zealand free of the wasp burden.
“German and common wasps can reach densities of over 350 wasps per square metre,” says Dr Darren Ward of Landcare Research.
“Wasps are so abundant in many native forests that they pose a major health and safety risk to those working and playing outdoors. They are voracious predators that cause declines in native biodiversity and reduce our ability to enjoy recreation activities.”
Professor Lester says efforts to control wasps are currently limited, although wasp control through bait stations could be an effective solution.
“We need to attack the wasp problem in the same way that we carry out intensive stoat and rat control in national parks but, unfortunately, the investment in getting these systems on to the market isn’t happening yet.”
Eric Edwards from the Department of Conservation agrees. “A large scale approach is needed and researching options for biological control, such as using pathogens and parasites over the one million hectares currently affected, is a wise investment in sustainable wasp control.”
Many at the workshop were surprised at the scale of New Zealand’s wasp problem and most participants had wasp-associated problems that needed a combined effort to find solutions for management.
The scientists who organised the workshop say it is clear that the impact of wasps on biodiversity warrants a well-funded investigative programme and benefits would extend to other sectors.
The workshop brought together researchers from Victoria University and Landcare Research along with people affected by wasps in conservation and recreation such as iwi, regional councils, pest control organisations, and the forestry and beekeeping sectors.
The first Vespula wasp to establish in New Zealand was the German wasp (V. germanica), which arrived in the Waikato with aircraft parts in 1945. The German wasp spread rapidly and became a significant pest.
The common wasp (V. vulgaris) is thought to have arrived in the late 1970s, but was unnoticed at first due to its similar appearance to the German wasp. The common wasp quickly replaced the German wasp in some environments and is now the most abundant species, particularly in the South Island.