CONTROL OF YELLOW TEA THRIPS (SCIRTOTHRIPS-DORSALIS HOOD) BY REFLECTIVE SHEET IN SATSUMA MANDARINE (CITRUS-UNSHIU MARC) ORCHARD

Control of Yellow Tea Thrips, Scirtothrips dorsalis by reflective shee t (RS) was examined in a satsuma mandarin (Citrus unshiu MARC.) orchar d in Shizuoka Prefecture,Japan in 1992 and 1993. The diffuse reflectan ce of RS at 290 nm to 800 nm was 84%-94%. RS was fully mulched on the ground in three orchards in the growing season. The percentage of grou nd occupancy by satsuma mandarin trees was 54.4%-60.5% and the mulchin g period was 4-7 months before harvest. Throughout the mulched period, the number of trapped thrips and the percentage of fruits infested by the thrips were continuously lower than EIL and the fruit damage at t he harvest time was low enough for high market quality. Conversely, he avy infestation and fruit damage were observed without RS. This sugges ts that RS mulching is a practical control measure for Yellow Tea Thri ps.