Start date: September 2002
End date: June 2014

Dr K Dhileepan, Ecosciences Precinct
k.dhileepan@deedi.qld.gov.au

Cat's claw creeper, an invasive liana native to Central and South America, is a major weed in coastal Queensland and New South Wales, where it poses a significant threat to biodiversity in riparian and rainforest communities. Cat's claw creeper is a structural parasite and produces stolons and subterranean root tubers. Biological control appears the most suitable management option for this weed. Management objectives focus on reducing the rate of shoot growth to limit the weed's ability to climb and smother native vegetation, as well as reducing tuber biomass to minimise the tuber bank.

• A map on the distribution of cat's claw creeper in South East Queensland and northern New South Wales was produced.
• Based on genetic studies, Paraguay was identified as the source country for the invasive cat's claw creeper populations in Australia and many other countries.
• A climate matching model (CLIMEX) identified areas in northern Argentina, southern Brazil, Uruguay and Paraguay as climatically suitable native range areas for biological control agent explorations.
• Simulated herbivory studies suggested that specialist herbivores in the leaf-feeding guild may be desirable in the biological control of cat's claw creeper. For the biological control agent to be effective, multiple consecutive defoliation events would be required.
• Following extensive host-specificity testing, two biological control agents, a leaf-sucking tingid (Carvalhotingis visenda) and a leaf-tying moth (Hypocosmia pyrochroma) were released across Queensland and northern New South Wales in partnership with community groups. Field releases have now concluded and both agents appear to have established successfully at numerous sites, but monitoring is ongoing.
• Also, we have completed host-specificity testing on a further agent, the leaf-mining buprestid beetle (Hylaeogena jureceki). Results indicate that this beetle is highly target-specific and can severely damage cat's claw creeper. We have submitted an application to Australian regulatory authorities to release this agent.
• Research into the characteristics of underground tuber banks in cat's claw creeper infestations revealed that tubers were abundant in terms of density, yet small in size and with few connections between them. This work suggests that new recruitment is primarily from seeds, not from vegetative propagation as previously thought. Future biological control efforts need to focus on introducing seed and pod-feeding insects to reduce seed output.
• Results from field studies on the growth of two cat's claw creeper varieties (long-pod and short-pod) at four field sites in south-eastern Queensland suggest that long-pod plants are more vigorous than short-pod plants, producing 40% more leaves. Above-ground biomass and total biomass were significantly greater for long-pod plants than short-pod plants at all sites. Biomass allocation also differed significantly; leaf mass ratio and stem mass ratio were higher and root mass ratio lower for long-pod plants than short-pod plants.

• Dhileepan, K, Treviño, M, Bayliss, D, Saunders, M, Shortus, M, McCarthy, J, Snow, EL, et al. 2010, 'Introduction and establishment of Carvalhotingis visenda (Hemiptera: Tingidae) as a biological control agent for cat's claw creeper Macfadyena unguis-cati (Bignoniaceae) in Australia', Biological Control 55(1): 58-62.
• Dhileepan, K, Bayliss, D and Treviño, M 2010, 'Thermal tolerance and potential distribution of Carvalhotingis visenda (Hemiptera: Tingidae), a biological control agent for cat's claw creeper, Macfadyena unguis-cati (Bignoniaceae)', Bulletin of Entomological Research 100(2): 159-66.
• Dhileepan, K, Treviño, M, Bayliss, D, Saunders, M, Shortus, M, McCarthy, J, Snow, EL and Walter, GH 2010, 'Introduction and establishment of Carvalhotingis visenda (Hemiptera: Tingidae) as a biological control agent for cat's claw creeper Macfadyena unguis-cati (Bignoniaceae) in Australia', Biological Control 55(1): 58-62.
• King, A and Dhileepan, K 2009, 'Clinging on: a review on the biological control of cat's claw creeper', Biocontrol News and Information 30(3): 53N-56N.
• Osunkoya, OO, Pyle, K, Scharaschkin, T and Dhileepan, K 2009, 'What lies beneath? The pattern and abundance of the subterranean tuber bank of the invasive liana cat's claw creeper, Macfadyena unguis-cati (Bignoniaceae)', Australian Journal of Botany 57(2): 132-8.
• Rafter, MA, Wilson, AJ, Senaratne, KADW and Dhileepan, K 2008, 'Climatic-requirements models of cat's claw creeper Macfadyena unguis-cati (Bignoniaceae) to prioritise areas for exploration and release of biological control agents', Biological Control 44(2): 169-79.
• Conrad, KA and Dhileepan, K 2007, 'Pre-release evaluation of the efficacy of the leaf-sucking bug Carvalhotingis visenda (Heteroptera: Tingidae) as a biological control agent for cat's claw creeper Macfadyena unguis-cati (Bignoniaceae)', Biocontrol Science and Technology 17(3): 303-11.
• Dhileepan, K, Snow, EL, Rafter, MA, Treviño, M, McCarthy, J and Senaratne, KADW 2007, 'The leaf-tying moth Hypocosmia pyrochroma (Lep., Pyralidae), a host-specific biological control agent for cat's claw creeper Macfadyena unguis-cati (Bignoniaceae) in Australia', Journal of Applied Entomology 131(8): 564-8.
• Dhileepan, K, Treviño, M and Snow, EL 2007, 'Specificity of Carvalhotingis visenda (Hemiptera: Tingidae) as a biological control agent for cat's claw creeper Macfadyena unguis-cati (Bignoniaceae) in Australia', Biological Control 41(2): 283-90.
• Raghu, S, Dhileepan, K and Scanlan, JC 2007, 'Predicting risk and benefit a priori in biological control of invasive plant species: a systems modelling approach, Ecological Modelling 208(2-4): 247-62.
• Raghu, S, Dhileepan, K and Trevino, M 2006, 'Response of an invasive liana to simulated herbivory: implications for its biological control', Acta Oecologica 29(3): 335-45.
• Raghu, S, Wilson, JR and Dhileepan, K 2006, 'Refining the process of agent selection through understanding plant demography and plant response to herbivory', Australian Journal of Entomology 45(4): 308-16.
• Dhileepan, K, Treviño, M, Donnelly, GP and Raghu, S 2005, 'Risk to non-target plants from Charidotis auroguttata (Chrysomelidae: Coleoptera), a potential biocontrol agent for cat's claw creeper Macfadyena unguis-cati (Bignoniaceae) in Australia', Biological Control 32(3): 450-60.
• Raghu, S and Dhileepan, K 2005, 'The value of simulating herbivory in selecting effective weed biological control agents', Biological Control 34(3): 265-73.

• Land Protection Fund
• Queensland Government (Blueprint for the Bush)

• Agricultural Research Council - Plant Protection Research Institute, South Africa
• The University of Queensland, School of Biological Sciences
• Queensland University of Technology, Science and Engineering Faculty
• Queensland Government Department of Environment and Resource Management
• Environmental Training and Employment Inc, New South Wales
• Local government and community groups across south-eastern and central Queensland