Septoria Leaf Spot of Lantana from Ecuador: A Potential Biological Control for Bush Lantana in Forests of Hawaii. Eduardo E. Trujillo, Department of Plant Pathology, Uni-versity of Hawaii, 3190 Maile Way, Honolulu 96822. David J. Norman, Assistant Researcher, Department of Plant Pathology, Uni-versity of Hawaii, 3190 Maile Way, Honolulu 96822. Plant Dis. 79:819-821. Accepted for publication 24 April 1995. Copyright 1995 The American Phytopathological Society. DOI: 10.1094/PD-79-0819.

Pathogenicity tests with a Seploria sp. isolated from Lantana camara from Ecuador showed aggressiveness to four L. camara selections from Hawaii forests. The initial symptoms of the disease on inoculated leaves were chlorotic spots that appear within 2 weeks, becoming dis-tinctly angular necrotic lesions in 4 weeks, inducing leaf chlorosis and defoliation 6 weeks after inoculation. Inoculum applied at 1 x 106 conidia per ml in 2% sucrose–0.5% gelatin solution produced an average of 87 lesions per leaf. Ornamental hybrids of L camara x L. montevidensis also were susceptible, but these plants had significantly fewer lesions. All selections of L montevidensis tested were immune. This Septoria sp. from Ecuador is the first pathogen found to be virulent on bush lantana, the most serious ecological threat to Kauai's forest, and its release is presumed to be an effective biocontrol agent for this weed.

Keyword(s): bioherbicide