SEPTORIA LEAF-SPOT OF LANTANA FROM ECUADOR - A POTENTIAL BIOLOGICAL-CONTROL FOR BUSH LANTANA IN FORESTS OF HAWAII

Pathogenicity tests with a Septoria sp. isolated from Lantana camara f rom Ecuador showed aggressiveness to four L. camara selections from Ha waii forests. The initial symptoms of the disease on inoculated leaves were chlorotic spots that appear within 2 weeks, becoming distinctly angular necrotic lesions in 4 weeks, inducing leaf chlorosis and defol iation 6 weeks after inoculation. Inoculum applied at 1 x 10(6) conidi a 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, hue these plants had significantly fewer lesion s. All selections of L. montevidensis tested were immune. This Septori a 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 .