INFESTATION AND DAMAGE CAUSED BY WESTERN FLOWER THRIPS (FRANKLINIELLA-OCCIDENTALIS PERGANDE) ON SATSUMA MANDARINE (CITRUS-UNSHIU MARC)

Infestation and damage caused by Western Flower Thrips (Frankliniella occidentalis PERGANDE) on satsuma mandarin (Citrus unshiu MARC.) were examined in 1993. The number of thrips infesting flowers was greatest at the end of blossoming. More eggs hatched from the pistil ovary and calyx than from the petal and stamen. Larva fed inside the calyx, and the damage resulted in young fruit rot as a result of fungal infection in the June rainy season. The economic damage caused by fruit rot can be minimized by fruit thinning. Adults could not survive on young fruits. Feeding on fruit was first observed when the color of peel oil spores changed to yellow and continued throughout the harvest period. Oviposition in the peel increased as the peel color changed from green to orange. Damaged fruit had many small spaces in the epidermis which appeared as whitish irregular dots. The color of frass on the peel was influenced by the color of the food peel. Shoot infestation was not observed.