Table 3. (continued) Scientific name (common name) WoNS Flora Base Naturalised in WA Reference to 26th parallel Locations Details Cylindropuntia imbricata rope cactus) Yes Yes Yes Both Goldfields, wheatbelt, Pilbara Outskirts of Buntine, Shire of Dalwallinu, abandoned houses and rubbish tips. Lallah Rookh, an outstation of Strelley Station, West Pilbara Cylindropuntia (Hudson pear) Yes Yes Yes Below No data The Menzies infestation of C. rosea is about 1.5 km x 1.5 km (~2.25 km2 or 225 ha) (Mac Jensen, DAFWA, pers. comm., March 2013) Cylindropuntia tunicata Yes Yes Goldfields Coolgardie Opuntia elata Yes Yes Yes Both No data Station infestation subject to eradication Opuntia elatior Yes Yes Yes Below Murchison The Wydgee Station infestation of O. elatior originated from a planting near the tennis court about 80 years ago. It has spread into a creek line and now covers about 200 ha. Opuntia engelmannii Yes Yes Yes Both No data Opuntia ficus-indica No Yes Below No data Naturalised in Carnarvon, Goldfields, Wheatbelt, Hills; common in cultivation
The problems caused by the extensive prickly pear (O. stricta) infestations in Queensland in the early 20th century are well known, and help identify opuntioid cacti as significant weeds, while the success of the O. stricta biological control program will drive community expectation that biological control programs for other opuntioid cacti will be equally successful. The recently-acquired WoNS status of the opuntioid cacti will help reinforce the community’s perception of their weed status. 3.4 Impact assessment for opuntioid cacti An impact assessment was conducted on four opuntioid cacti species and the entire genus Opuntia as part of a process to undertake Benefit Cost Analysis for all declared plants and WoNS weeds present in WA (Petersen et al., 2013). This assessment involved an expert panel approach, where weed specialists used their knowledge of the benefits of control to score each plant on a scale of 1 to 5, using the key shown in Table 4. A total of 73 declared plant species were assessed. Agricultural and environmental benefits were scored separately. Both private (landholder) and public (government and the community) benefits were considered. The agricultural and environmental benefit score given by all experts was averaged (that is, given equal weight in terms of benefits) to calculate an Impact Score as shown in Table 5. Table 4. Scoring key for measuring benefits of plant control Agricultural benefits Environmental benefits 1 – Uncontrolled plant has very little impact on profit 1 – Uncontrolled plant has very little impact on environment 2 2 3 – Moderate 3 – Moderate 4 4 5 – Uncontrolled plant has significant impact on profit 5 – Uncontrolled plant has significant impact on environment 5. Impact scores and rankings for opuntioid cacti Common name(s) Scientific name Agric impact Ranking (out of 73) Enviro impact Ranking (out of 73) Cane or cactus Austrocylindropuntia cylindrica 3.0 16= 3.5 28=
Mitigation strategy Support and partner with NRM, DPaW, local government and industry to encourage a statewide cactus coordinator to record all WA information. Support a working group or other coordinating body for cactus management. Risk 2 − Action is not to eradicate infestations of opuntioid cacti that are at the early stage of invasion and are potentially eradicable. Mitigation strategy Support and partner with funding bodies to prepare funding applications that allow for the control of early stage infestations. Risk 3 – The opuntioid cacti will invade much larger areas of the state than are currently occupied, especially in the southern rangelands. Mitigation strategy Support and partner with funding bodies to prepare funding applications to contain large infestations. If available, support the release of biocontrol agents to manage large or dense infestations. Risk 4 – Biological control agents are not available for the main species. Mitigation strategy Partner with agencies searching for new biological control agents. Facilitate rearing and release of biological control agents when available. Risk 5 – Most opuntioid cacti are not declared, making compliance and enforcement an issue for sale, supply and movement. Mitigation strategy Ensure appropriate declaration is in place under the BAM Act. 7. (continued) Risk 6 – Information on basic biology and ecology of opuntioid cacti is not adequate. Mitigation strategy Provide scientific expertise where staff and resources allow. Encourage universities and other organisations to carry out research on opuntioid cacti. Risk 7 – Technical information for control such as and rates of herbicides, timing of application, and use of additives and adjuvants is not adequate. Mitigation strategy Provide technical expertise where staff and resources allow.
St Barbara Mines Mapping the infestation, installing fence, spraying outlying patches, funding for Cactus Forum. Corralling the Coral Cactus project, Tarmoola Station, Shire of Leonora. St Barbara Mines Management research. Herbicide demonstration (MSMA) on Tarmoola Station. Rangelands NRM (in partnership with Goldfields Nullarbor Regional Biosecurity Association) $100K for various activities including fencing off infested area to prevent further spread (see below). Corralling the Coral Cactus project on Cylindropuntia fulgida var. mamillata, Tarmoola Station, Shire of Leonora. Rangelands NRM (in partnership with Goldfields Nullarbor Regional Biosecurity Association) Funding for management research. Herbicide demonstration plots for C. fulgida var. mamillata, C. imbricata and an unknown Opuntia sp. on Tarmoola Station and C. rosea on the Menzies tip in June and September 2013. Table 8. (continued) Stakeholder Management Action Details
Goldfields Nullarbor Regional Biosecurity Association (GNRBA) Liaising with various stakeholders, sourcing funds, delivering projects. Delivered projects including the fencing on Tarmoola Station, and herbicide demonstration on Tarmoola Station and at Menzies tip. More information will be available by the end of 2014. Goldfields Nullarbor Regional Biosecurity Association Negotiating with governments (directly and through GVROC) and other organisations on control of opuntioid cacti. Some projects are expected to commence in 2014. More information will be available by the end of 2014. St Barbara Mines (in partnership with Goldfields Nullarbor Regional Biosecurity Association) Release site for biological control agent Dactylopius tomentosa. The C. fulgida var. mamillata infestation at Tarmoola Station has been offered as a nursery site for rearing the biological control agent when it becomes available. Goldfields Voluntary Regional Organisation of Councils (GVROC) The City of and Shires of Coolgardie, Dundas, Esperance, Laverton, Leonora, Menzies, Ngaanyatjarraku, Ravensthorpe and Wiluna. Discussed opuntioid cacti at their November 2013 meeting. Interested in collaborating with each other, with GNRBA, DAFWA and DPaW. More information will be available later in 2014. The Shires of Laverton, Leonora, Menzies and Wiluna in partnership with the Goldfields Nullarbor Regional Biosecurity Association and Invasive Species staff Allocated funding in the local government budget in 2013-14. Spraying cactus infestations and other control work in Goldfields Shires. More information will be available later in 2014. Shire of Menzies and Goldfields Nullarbor Regional Biosecurity Association (proposed project) Control Control of C. infestation on the Menzies tip. Lyndon LCDC, with NRM funding (proposed project) Cactus control on Mardathuna Station $20,000 for cactus control (probably C. fulgida var. mamillata). Table 8. (continued)