Target pest: Arundo donax (Poales: Poaceae), Giant reed
Agent introduced: Rhizaspidiotus donacis (Hemiptera: Diaspididae), Arundo scale
Landcare Research (2017c) - the opportunity to utilise R. donacis in New Zealand arose opportunistically after it was imported into containment in Auckland as part of a Cook Islands project and it was subsequently found that giant reed in the Cook Islands had been confused with the similar-looking elephant grass.
Landcare Research (2018i) - first field release planned for spring 2018.
Landcare Research (2019i) - first field release now planned for spring 2019.
Landcare Research (2020g) - first field release now planned for spring 2020.
Landcare Research (2021e, 2021f) - first field releases made in early 2021; two releases made in the year Sep 2020 - Aug 2021.
Landcare Research (2022h) - two releases made in the year Sep 2021 - Aug 2022.
Landcare Research (2021f) - establishment success unknown (as of Aug 2021).
Impacts on non-targets:
Landcare Research (2016k, 2017c) - R. donacis is highly host specific and is expected to attack only giant reed in New Zealand. Significant testing before this agent was released in the USA indicated it was specific to A. donax in the field, but might produce occasional offspring on a few closely-related species. Although New Zealand has no native species in the same sub-family (Arundinoideae) as A. donax, three native species (the endemic Isachne globosa and Zoysia minima, and the indigenous Spinifex sericeus) representing the sub-families most closely related to the Arundinoideae (Chloridoideae and Micrairoideae) were tested, and found to be unsuitable hosts.
EPA (2017a) - 12 Sep 2016: application by Northland Regional Council to introduce a gall forming wasp (Tetramesa romana) and a scale insect (Rhizaspidiotus donacis) to control giant reed (Arundo donax). EPA Application # APP202887, approved without controls 17 Jan 2017.
EPA (2017a). EPA application APP202887: to introduce a gall forming wasp (Tetramesa romana) and a scale insect (Rhizaspidiotus donacis) to control giant reed (Arundo donax). Environmental Protection Authority website https://www.epa.govt.nz/database-search/hsno-application-register/view/APP202887
Landcare Research (2016k). The host ranges of Tetramesa romana and Rhizaspidiotus donacis, potential control agents for giant reed, Arundo donax. http://www.landcareresearch.co.nz/__data/assets/pdf_file/0017/112742/The-host-range-testing-for-giant-reed.pdf
Landcare Research (2017c). Tiny insects to attack giant reed Weed Biocontrol: What's New? 80: 4-5 http://www.landcareresearch.co.nz/__data/assets/pdf_file/0013/141133/Issue-80.pdf
Landcare Research (2018i). Who's who in biological control of weeds? Weed Biocontrol: What's New? 85, August 2018 https://www.landcareresearch.co.nz/publications/newsletters/biological-control-of-weeds/issue-85/whos-who-in-biological-control-of-weeds
Landcare Research (2019i). Who's who in biological control of weeds? Weed Biocontrol: What's New? 89, August 2019 https://www.landcareresearch.co.nz/publications/newsletters/biological-control-of-weeds/weed-biocontrol-issue-89/whos-who-in-biological-control-of-weeds
Landcare Research (2020g). Who's who in biological control of weeds? Weed Biocontrol: What's New? 93, Aug 2020. https://www.landcareresearch.co.nz/publications/weed-biocontrol/weed-biocontrol-articles/status-of-agents/
Landcare Research (2021e). Further reading and agents released. Weed Biocontrol: What's New? 97, August 2021 https://www.landcareresearch.co.nz/publications/weed-biocontrol/weed-biocontrol-articles/further-reading
Landcare Research (2021f). Who's who in biological control of weeds? Weed Biocontrol: What's New? 97, August 2021 https://www.landcareresearch.co.nz/publications/weed-biocontrol/weed-biocontrol-articles/whos-who-in-biological-control-of-weeds
Landcare Research (2022h). Further reading and agents released 2021/22. Weed Biocontrol: What's New? 101, August 2022 https://www.landcareresearch.co.nz/publications/weed-biocontrol/weed-biocontrol-articles/further-reading-and-agents-released-202122/