Biological Control of the European Wasp in Australia

This Benefits Transfer study undertaken by the AERU is part of a broader project by CEBRA and the Australian Government aimed at delivering updated knowledge on the benefits and costs of biological control of established pests in Australia, of which the European Wasp (Vespula germanica) is a prime candidate. This project explored the benefits and costs of European wasp management using a decision analysis model, where ‘management’ included the use of biocontrol agents that have already been cleared for release in Australia.

The non-market valuation method of Benefit Transfer is used to incorporate the social and environmental impacts of the European wasp into the model. Including Benefits Transfer in the analysis allows for an assessment of the magnitude of measurable non-market impacts, and whether their inclusion changes the business case.

Management of the European Wasp provides two main types of non-market environmental and social benefits. First, due to their scavenging habits and choice of nesting sites, they are frequently attracted to homes, recreation areas, and garden and picnic areas, where they pose a sting threat and create nuisance. Second, wasps create immediate impacts on native biodiversity by predation of various insects and spiders, and by competing with native species for these food resources.

Conducting primary valuation studies can be relatively time and resource intensive and so Benefits Transfer is an approach to valuation that uses valuation estimates from relevant primary studies already conducted and published, and applies them to the new management context.

In our study, we develop a spatially sensitive Benefit Transfer model using values derived from a Choice Modelling study of public preferences for Red Imported Fire Ant management in Brisbane. The Benefit Transfer model adjusts source study values according to variations in the geographic location of wasp spread and the level of resultant management efforts, and for differences in demographics of households benefiting from management efforts.

A key finding was that non-market impacts of European wasp outweigh market impacts. Without a formal management programme, the impacts on biodiversity, use of public places for recreation and human health were estimated to be more than one-and-a-half times the market impact over a 50-year period.