Staff Assessment Report APP203542: An application to release two moths (Wheeleria spilodactylus and Chamaesphecia mysiniformis) as biological control agents for the weed horehound (Marrubium vulgare). August 2018 To introduce two moths, Wheeleria spilodactylus and Chamaesphecia mysiniformis to Purpose control the weed horehound (Marrubium vulgare). APP203542 Application number Notified, Full Release Application type Horehound Biocontrol Group Applicant 15 May 2018 Date formally received 2 EPA advice for application APP203542 Executive Summary and Recommendation In May 2018, the Horehound Biocontrol Group made an application to the Environmental Protection Authority (EPA) seeking to introduce two moths, Wheeleria spilodactylus (the plume moth) and Chamaesphecia mysiniformis (the clearwing moth), as biological control agents for the weed horehound (Marrubium vulgare). We assessed the benefits (positive effects) and risks and costs (adverse effects) of introducing the two biocontrol agents to New Zealand and found that the benefits relating to environmental outcomes to be significant and the adverse effects negligible (Kaser & Ode 2016). We consider it likely that biological control of horehound will improve biodiversity values and conservation of protected natural habitats. We also consider it highly likely that biocontrol of horehound will reduce the costs of farming relating to crop replacement and wool processing. We note that this biocontrol programme could reduce the dispersal of the weed into sensitive environments. We consider it highly improbable for the plume moth and the clearwing moth to pose risks to native or valued plants in New Zealand. There are no native species in the Marrubium genus and, no other valued species within this genus in New Zealand. Host range experiments confirmed their narrow host specificity. We also evaluated the possible indirect effects of the two agents, including apparent competition, and found it very unlikely for the plume moth and the clearwing moth to have adverse impacts on ecosystems. We consider the potential economic risks that may occur following the release of the biocontrol agents in New Zealand and found that it is very unlikely that herbalists and their business interests would be adversely affected by the release of the two agents. The EPA staff assessment report also discusses the effects of the two insects on the relationship of Māori to their environment, and measures the agents against the minimum standards in the Hazardous Substances and New Organisms Act (HSNO Act). We conclude that the plume moth and the clearwing moth meet the minimum standards. Our assessment found the benefits of releasing the plume moth and the clearwing moth outweigh any identified risks and costs and recommend that the application be approved. August 2018 3 EPA advice for application APP203542 Table of contents Purpose of this document 4 Application process 4 Submissions 4 Submissions from DOC and MPI 4 The biology and ecology of Marrubium vulgare ……………………………...………………………………..5 Impact of horehound on the environment 6 Distribution/status of horehound around the world 7 Distribution in New Zealand 8 Current strategies to control horehound 9 Organisms proposed for release …………………………………………………………................................10 The native range and biology of the plume moth (Wheeleria spilodactylus) 10 The native range and biology of the clearwing moth (Chamaesphecia mysiniformis) 11 The impacts of plume moth and clearwing moth on horehound in Australia 11 Climate favourable for plume moth and clearwing moth establishment 12 Risk assessment ……………………………………………………………………………………………………..13 Assessment of benefits 14 Our assessment of the potential environmental benefits 14 Environmental benefits of horehound in the absence of the biocontrol agents 14 Environmental benefits of the two biocontrol agents 15 Our assessment of the potential economic benefits 17 Economic benefits of horehound in the absence of the biocontrol agents 17 Economic benefits of the two biocontrol agents 18 Assessment of risks 20 Our assessment of the potential environmental risks 20 Environmental risks of horehound in the absence of the biocontrol agents 20 Environmental risks of the two biocontrol agents 21 Our assessment of the potential economic risks 24 Economic risks of horehound in the absence of the biocontrol agents 24 Economic risks of the two biocontrol agents 24 Conclusion on benefits and risk assessment 27 Relationship of Māori to the environment ………………………………………………………………………28 Consideration of the Māori Reference Group 26 Consultation with Te Herenga 26 Minimum Standards …………………………………………………………………………...............................26 Additional matters to be considered 27 Recommendation ………………………………………………………………………….………………………...27 References 28 Internet references 32 Appendix 1: Summary of submissions 33 Appendix 2: Cultural Risk Assessment for New Organisms Application 40 August 2018 4 EPA advice for application APP203542 Purpose of this document 1. On 15 May 2018, the Horehound Biocontrol Group applied to the Environmental Protection Authority (EPA) to introduce two moths, Wheeleria spilodactylus and Chamaesphecia mysiniformis, as biological control agents for the weed horehound (Marrubium vulgare). 2. This document has been prepared by EPA staff to advise the Decision-making Committee on our risk assessment for the release of the moths. The document discusses the information provided in the application, information readily available in scientific literature, and information submitted to the EPA during the public notification process. Application process 3. The Horehound Biocontrol Group lodged an application with the EPA on 15 May 2018 seeking approval to release the two moths under section 34 of the Hazardous Substances and New Organisms (HSNO) Act (the Act). 4. The application was publicly notified, and open for submissions for 30 working days on 29 May 2018 as required by section 53(1)(b) of the Act. The submission period ended on 11 July 2018. Submissions 5. We received forty submissions on this application. The submissions are summarised in Appendix 1. Thirty-nine submitters including farmers, regional councils, and government agencies support the application and one submitter, a herbal company, oppose the application. Eight submitters indicated they wish to be heard. Submissions from DOC and MPI 6. As required by the Act and the Hazardous Substances and New Organisms (Methodology) Order 1998, the Ministry for Primary Industries (MPI) and the Department of Conservation (DOC) were notified of the application and provided with the opportunity to comment. 7. MPI supports the application. They note the negative impact of chemicals on the environment and the benefit that biocontrol agents offer in the long term. MPI recognises that the release of the two moth species is unlikely to eradicate all horehound from New Zealand. 8. DOC supports the application due to the high host specificity of the moths and success of the two agents against horehound in Australia, but do not support the general approach with the testing being done in Australia. They would prefer to see testing being conducted on native New Zealand species and not surrogate species only. August 2018 5 EPA advice for application APP203542 Horehound as the target weed The biology and ecology of Marrubium vulgare 9. Horehound is a tall (25 to 60 cm) perennial herb in the mint family. Native to the temperate Mediterranean region and central and western Asia, it is widely naturalised in the United States and South America as well as Australia and New Zealand. It was introduced in Australia and elsewhere by settlers as a useful garden herb, for beer brewing and for medical purposes. It most likely escaped cultivation to rapidly become a major weed for pasture (Weiss et al. 2000). 10. Horehound has dense clusters of small white flowers that form brown burrs with small hooked spines. Each burr contains four small spear-shaped seeds. The burr easily attaches itself to anything that comes into contact (e.g. wool, fur, clothing, tyres) enabling effective seed dispersal. Water channels and horse faeces are other effective natural dispersing agents for the seeds (Weiss et al. 2000). 11. Mature plants are multi-stemmed with up to 200 individual stems and can produce more than 20,000 seeds a year. The seeds stay viable for 7 to 10 years in the soil (Weiss et al. 2000). Horehound has the ability to disperse effectively via rhizomes and seeds (Stritzke 1975). Most seeds germinate with the first autumn rainfall and through winter. In spring, the plant flowers and is primarily bee-pollinated (Weiss & Sagliocco 2011). 12. Horehound can grow in various climates from arid to high-rainfall zones (Weiss & Sagliocco 1994). It thrives in disturbed areas like waste places, roadsides, along fence lines, fields extensively grazed by sheep, as well as native grasslands where competition with other plants is limited (Weiss et al. 2000). It is often the first plant to colonise eroded areas (Parsons et al. 2001). Horehound can be found in infertile soils and is tolerant to drought and frost conditions. The soil moisture availability can be a limiting factor for germination, however, mature plants seem to be able to survive dry conditions (Lippai et al. 1996). Table 1: Complete taxonomic description of horehound Taxonomic Unit Classification Phylum/Division Spermatophyta Class Dicotyledonae Order Lamiales Family Labiatae (formally known as Lamiaceae) Sub-family Lamioideae Genus Marrubium