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 93 .