Biological control of the ivy gourd, Coccinia grandis (Cucurbitaceae) in the Marianas Islands. G.V.P. Reddy and R. Muniappan, Agricultural Experiment Station, University of Guam, Mangilao, Guam

The invasive plant, ivy gourd, Coccinia grandis (L.) Voigt (Family: Cucurbitaceae, Order: Violales) is of African origin and was introduced to Guam and Saipan in the 1980s. It has occupied over 200 acres in different parts of Guam and almost one third of the land area of Saipan. This plant forms thickets, suppresses roadside vegetation, occupies fence lines and becomes a weed on horticultural crops such as lemon, mango, and banana. A biological control program has been initiated in Guam and Saipan following the success achieved in Hawaii by introducing the natural enemies Melittia oedipus Oberthor (Lepidoptera: Sessidae), Acythopeus burkhartorum O’brien and Pakaluk (Coleoptera: Curculionidae) and Acythopeus cocciniae O’brien and Pakaluk (Coleoptera: Curculionidae). The APHIS and USDA has accepted the list of species used for host specificity tests in Hawaii and it was decided that the endemic species, Zehnaria guamensis (Cucurbitaceae) be tested in Guam. Host specificity tests of A. cocciniae and A. burkhortorum on Z. guamensis were conducted at the quarantine facility in Guam. In May 2003, A. cocciniae was field released in Guam and Saipan. It has well established in both the islands and caused defoliation of C. grandis by the larval mining of the leaves. Acythopeus burkhortorum has been field released in Guam in October 2004 and on Saipan in February 2005. Its field establishment on Guam has been confirmed and its establishment in Saipan is yet to be verified.