Establishment of Strawberry Guava Biocontrol in Hawaii M

Session 4 Abstracts

Establishment of strawberry guava biocontrol in Hawaii M. Tracy Johnson* and Nancy L. Chaney USDA Forest Service, PO Box 236, Volcano, HI 96785, USA. [email protected]

Strawberry guava, Psidium cattleianum (Myrtaceae), is a fast-growing Brazilian fruit tree that is a major threat to wet forests in Hawaii and other tropical islands. The biocontrol agent Tectococcus ovatus (Hemiptera: Eriococcidae), a leaf-galling scale insect from Brazil, was released and established in demonstration plots in Hawaii during 2012. The agent has begun to reproduce and spread within individual trees at these sites, although population growth is notably slower in Volcano (1200m elevation) compared to Hilo (150 m elevation). These initial release sites are within common gardens planted with three well-known genotypes of strawberry guava (red, yellow and spindle-fruited) to demonstrate impacts and specificity of the biocontrol agent. Results so far indicate that all three genotypes are susceptible to T. ovatus. Releases into forest sites were begun in 2013 at the request of land managers state-wide, who view biocontrol as an essential tool for slowing the spread of strawberry guava across hundreds of thousands of acres of native forest. Methods for establishing and dispersing the agent efficiently are under development. Our Hawaii program is designed to demonstrate the safety and effectiveness of this new biocontrol agent, to monitor its impacts in rainforest plots along invasion fronts, and to develop strategies for integrating biocontrol with restoration of already degraded forest areas state-wide. We also are beginning a project to monitor the potential for strawberry guava biocontrol to suppress a major agricultural pest, the fruit fly Bactrocera dorsalis (Diptera: Tephritidae), which develops in seasonally abundant P. cattleianum fruits and then invades dozens of fruit crops.

Release and initial establishment of a seed-feeding weevil, Cissoanthonomus tuberculipennis, a biological control agent for balloon vine, Cardiospermum grandiflorum, in South Africa David O. Simelane*1, Khethani V. Mawela1 and Maria S. Ferrucci2 1Agricultural Research Council - Plant Protection Research Institute, Private Bag X134, Queenswood 0121, South Africa. [email protected] 2Instituto de Botanica del Nordeste, IBONE, Facultad de Ciencias Agrarias Universidad Nacional del Nordeste Sgto, Cabral 2131, C.C. 209 3400, Corrientes, Argentina.

After 10 years of research, approval to release a seed-feeding weevil, Cissoanthonomus tuberculipennis (Coleoptera: Curculionidae), against balloon vine, Cardiospermum grandiflorum (Sapindaceae), in South Africa was granted by the Department of Agriculture, Forestry and Fisheries in July 2013. Over 400 C. tuberculipennis, ranging from larval to adult stages, were collected from the native range in Corrientes province of Argentina in March 2013. Field release of the weevil commenced in August 2013 in South Africa, and since then over 450 C. tuberculipennis adults have been released at nine sites located in KwaZulu-Natal (KZN), Limpopo and Gauteng provinces, with 50 adults released per site. Of these, initial establishment has been recorded at eight sites in KZN and Gauteng, with seed-predation ranging from 5-30% per site. Seed predation by C. tuberculipennis was also conducted in an open-field, in the native range, to determine the contribution of this weevil to seed destruction in relation to other seed feeders. Cissoanthonomus tuberculipennis alone destroyed up to 44% of seeds per site despite competitive interactions with other seed-attacking insects in the native range. Lack of seed-feeding competitors of C. tuberculipennis on C. grandiflorum in South Africa is likely to increase the reproductive output of this weevil and thereby increase levels of seed destruction.

Progress on the biological control of two of Hawaii’s worst invasive alien species Djamila H. Djeddour*1, Robert A. Tanner1, Corin Pratt1 and Tracy Johnson2 1CABI Europe-UK, Bakeham Lane, Egham, Surrey, TW20 9TY, United Kingdom. [email protected] 2Hawaii Volcanoes National Park Quarantine Facility, Institute of Pacific Islands Forestry, USDA Forest Service, P.O. Box 236, Volcano, 96785 Hawaii, USA.

The Himalayan yellow raspberry, Rubus ellipticus var. obcordatus (Rosaceae), and Kahili ginger, Hedychium gardnerianum (Zingiberaceae) are two of the most serious threats to the unique habitat of the Hawaiian Islands. Considered beyond chemical and mechanical control, these large, thicket-forming invasive plants are capable of altering ecosystem processes and displacing

Session 4 Abstracts natives across a range of habitats, including native montane rain forests. Both species are extraordinarily adaptable and aggressive vegetative-colonisers whose fruits are also readily dispersed by birds. Both are of Asian origin and are valued as ornamental plants in the Hawaiian community. Although mechanical and herbicidal control has been performed on a limited scale for both species, large-scale eradication is not feasible across such rugged terrain and the infested areas are increasing. Classical biological control is widely believed to be the only long-term solution to both these intractable invaders. A biocontrol initiative for Kahili ginger was initiated by CABI in 2008 for Hawaii and for New Zealand, whilst the Rubus biocontrol prospects for Hawaii are being rekindled focusing on natural enemies from the western Himalayas. This poster provides a review of the biological control efforts undertaken to date for Hawaii and elsewhere, as well as the potential of some of the arthropod and fungal agents that are under investigation.

Biological control of the environmental weed Madeira vine in Australia W.A. Palmer*, E.L. Snow and K. Dhileepan Biosecurity Queensland, Department of Agriculture, Forestry and Fisheries, Ecosciences Precinct, GPO Box 267, Brisbane, Qld 4001, Australia. [email protected]

Australia commenced a small biocontrol project against the South American invasive, Madeira vine, Anredera cordifolia (Basellaceae), following the finding of two potential agents in Argentina by South African and local scientists. Two beetle species (Coleoptera: Chrysomelidae) were then imported into quarantine in Queensland from laboratory cultures in South Africa: (i) Phenrica species did not prosper in Australia under quarantine conditions and the colony soon died out as did, ultimately, the South African culture, and later efforts to find new populations in Argentina were unsuccessful; (ii) in contrast, Plectonycha correntina (Coleoptera: Chrysomelidae) was very successfully cultured and considered highly promising. Host range studies on P. correntina indicated its safety for release in Australia and it has now been widely distributed in Queensland and northern New South Wales. Establishment has been partially successful, on occasion causing significant damage, but the ultimate effect of this agent is not yet known. New priorities, following a change in government in Australia, place less emphasis on environmental weeds such as Madeira vine and it is therefore unlikely that further effort will be made against A. cordifolia.

Post release evaluation of Anthonomus santacruzi and Gargaphia decoris released against bugweed, Solanum mauritianum in the Lowveld of South Africa Archbold Sasa*, Marcus Byrne and Edward Witkowski School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg 2050, South Africa. [email protected]

Bugweed, Solanum mauritianum (Solanaceae), is a South American invasive perennial weed of economic and ecological importance, mainly in the high rainfall regions of South Africa (Category 1 of the Conservation of Agricultural Resources Act). Chemical and mechanical control methods have not proved cost-effective in controlling this weed, hence biological control was introduced. Two biocontrol agents, Gargaphia decoris (Hemiptera: Tingidae) and Anthonomus santacruzi (Coleoptera: Curculionidae) were released in South Africa in 1999 and 2008 respectively, with establishment reported in some regions. A post-release evaluation of these biocontrol agents to assess their impact on bugweed’s population growth and reproduction was carried out seasonally from December 2012 to November 2013. The study also looked at the effects of biotic and abiotic habitat characteristics on the growth and spread of the biocontrol agents on populations of bugweed. The approach to the study was observational field studies using 12 ‘riparian’ plots (six release, and six non-release) and 12 ‘plantation’ plots (six release, and six non-release) in the Lowveld (Sabie River catchment area of Mpumalanga Province, South Africa). In each plot (20 m x 50 m) five ‘permanent’ >2m tall plants were selected and used throughout the study. Insecticide exclusion, carbofuran at 10 g per plant once every season was used to exclude the biological control agents on the selected plants in the control (non-release) plots.