Locally Established Botrytis Fruit Rot of Myrica fay a, a Noxious Weed in Hawaii. BRION K. DUFFY, Former Research Associate, Cooperative Park Studies Unit, National Park Service, Department of Botany, University of Hawaii at Manoa, Honolulu 96822. DONALD E. GARDNER, Research Plant Pathologist, Cooperative Park Studies Unit, National Park Service, Department of Botany, University of Hawaii at Manoa, Honolulu 96822. Plant Dis. 78:919-923. Accepted for publication 8 June 1994. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1994. DOI: 10.1094/PD-78-0919.

Faya (Myricafaya) is an introduced weedy tree threatening native ecosystems in Hawaii. Classical biological control has been investigated for several years but has yielded few insect pests or pathogens, none of which currently offers control in the field. As an alternative, attention was recently given to identify locally established insect pests and pathogens. Botrytis cinerea causes widespread fruit rot and is the first pathogen reported from faya in its nonnative habitat. Infection of flowers and foliage is rarely observed. Fruit rot occurs on trees of all sizes in a variety of habitats throughout the Hawaiian range of faya. In 1992, over 49 and 51% of mature fruit at two sites were infected. Similar percentages of immature fruit were infected or infested with B. cinerea. Adults and fruit-feeding larvae of Amorbia emigratella and Crypto-blabes gnidiella collected from infected fruit clusters in the field were heavily infested with viable conidia and may serve as vectors. Selection of more aggressive or ecologically fit strains or introduction of large numbers of Botrytis-infested insect vectors early in the fruiting season may enhance faya biocontrol.

Keyword(s): Anemone hupehensis, fungal vectors, Penicillium dendriticum, Styphelia tameiameiae, Vaccinium reticulatum, weed biological control