Staff Assessment Report APP203875: An application to import and release two biological control agents to control German and common wasps. Purpose To release two parasitoids, Metoecus paradoxus and Volucella inanis, as biological control agents for the invasive German and common wasps (Vespula germanica and V. vulgaris). Application number APP203875 Application type Notified, Full Release Applicant Tasman District Council Date formally received 14 September 2020 1 EPA advice for APP203 875 Executive Summary and Recommendation In September 2020, the Tasman District Council on behalf of the Vespula Biocontrol Action Group submitted an application to the Environmental Protection Authority (EPA) seeking pre-approval to release two biological control agents (BCAs) for the German wasp and the common wasp. The research and background study was conducted by Manaaki Whenua Landcare Research New Zealand Limited. The application was publicly notified. The EPA received 30 submissions, 25 submissions supported the application, two submissions neither supported nor opposed and three submissions opposed the application. The EPA assessed the risks, costs and benefits of the release of the two BCAs in the context of the environment, market economy, people and communities, public health and on the relationship of Māori and their culture and traditions with their ancestral lands, water, sites, wāhi tapu, valued flora and fauna, and other taonga. Regarding the environment, we assessed that the benefits from the release of the BCAs would be highly likely to improve biodiversity and reduce the amount of fertiliser used by the pastoral sector. We noted that the impact would be major in areas highly infested by wasps. We concluded that the release of these BCAs could potentially have a high impact on the environment with the decrease of chemical usage and the re-emergence of the native biodiversity. Regarding the economy, we assessed the benefits would be highly likely to have minor to moderate regional economic impact for apiarists and farmers depending on the degree of infestation, via the reduction of wasp impact cost on bees and the increase of honey production. In addition, the increase in natural pollination would reduce the quantity of fertiliser and sowing needed by the pastoral industry. We noted that the BCAs are also likely to have a minor to moderate regional impact on the tourism industry with the sustainability of tourist attractions and the decrease of the cost associated with the management of wasps. We concluded that the release of the two BCAs could have a low to medium impact on the market economy depending on the region and the level of wasp infestation. Regarding public health benefits, we considered that if the introduction of the two BCAs is successful, there is likely to be a reduction in the number of people encountering pest wasps. This in turn is likely to reduce the number of severe allergic reactions leading to death and traffic accidents attributed to wasps. However, casualties would not be eliminated from the release of the BCAs. We concluded that from the individual’s perspective, the benefits could be significant for those who are highly allergic to wasps, whereas it would be low at the general community level. Regarding people and communities, the release of the BCAs is likely to have moderate impacts locally where large wasp infestations exist. Overall, the level of benefits on the community would be low to medium at the local and national levels. Regarding the risk for the environment, we assessed that the release of the two BCAs is unlikely to impact the amount of pesticides used in organic gardens or to impact native species or valued exotic species due to the host specificity of the two BCAs. We noted that V. inanis is likely to increase competition for pollen and nectar and could have a minor impact on the food-webs, however, we considered that the mitigation of wasp populations would have lesser adverse effects. We noted that the two BCAs are highly unlikely to hybridise with native species in the absence of species in the same genus. We concluded that any adverse effects on the environment would be minimal to minor and the effects are expected to be low. Regarding the economy, we concluded that the release of the BCAs is likely to have a minimal adverse impact on pesticides sellers and a minor adverse impact on pest control companies especially 2 EPA advice for APP203 875 for regions highly infested by wasps. Overall, we concluded that the level of risks on New Zealand’s market economy is low. Regarding public health, we considered that the release of the two BCAs is highly improbable to have adverse effects as neither BCAs sting or are known to vector diseases. The overall level of risks is assessed to be negligible. The application was also assessed against the minimum standards in the HSNO Act, and the EPA concluded that the two BCAs meet the minimum standards. The potential risks to Māori interests from the release of the BCAs are likely to be acceptable in terms of Māori cultural beliefs and environmental frameworks. We found the benefits of the release of the two BCAs outweigh the risks and costs. We recommend the decision-making committee approve the release of Metoecus paradoxus and Volucella inanis as biological control agents for Vespula germanica and V. vulgaris. 3 EPA advice for APP203 875 Contents Purpose of this document ..................................................................................................................... 6 Application process .............................................................................................................................. 6 Submissions ......................................................................................................................................... 6 The target hosts ............................................................................................................................................................7 Vespula vulgaris ...................................................................................................................................8 Biology and ecology ......................................................................................................................... 8 Habitats and distribution ................................................................................................................... 9 Vespula germanica ............................................................................................................................ 10 Biology and ecology ....................................................................................................................... 11 Habitats and distribution ................................................................................................................. 11 Current strategies to control V. vulgaris and V. germanica ............................................................... 12 The proposed biological control agents ............................................................................................................... 14 Volucella inanis (Linnaeus, 1758)...................................................................................................... 14 Metoecus paradoxus (Linnaeus, 1761) ............................................................................................. 15 Acclimation to New Zealand .............................................................................................................. 17 Host specificity ............................................................................................................................................................ 18 Phylogeny .......................................................................................................................................... 18 Behaviour: social versus solitary ....................................................................................................... 19 Life cycle ............................................................................................................................................ 20 Nesting ............................................................................................................................................... 21 Habitat ............................................................................................................................................... 21 Mimicry .............................................................................................................................................. 22 Host-range testing ............................................................................................................................. 23 Conclusion ......................................................................................................................................... 23 Risk assessment ....................................................................................................................................................... 24 Potential benefits from the release of the BCAs ................................................................................ 24 Environment ................................................................................................................................... 24 Economy ......................................................................................................................................... 28