Occurrence of Blemished Fruits Caused by Thrips tabaci on Greenhouse Satsuma Mandarins in Shizuoka Prefecture

Abstract

White blemishes occurred on the rind of Satsuma mandarin fruits cultivated in greenhouses of Numazu City, Shizuoka Prefecture in 2000. Blemished fruits were present in 21 greenhouses (70% of all greenhouses within the city) with an area of 134 a (81.2% of total greenhouse area). All insects collected from 7 damaged Satsuma mandarin fruits were identified as Thrips tabaci. This species accounted for 95.2% of all insects, 720 individuals, collected on yellow sticky-traps from 25 May to 7 June in a greenhouse. Experimental infestation of T. tabaci adults collected from leek caused the same kind of damage on ripe Satsuma mandarin fruits. T. tabaci made minute vacant spaces in the rind by piercing and sucking the surface tissues and the blemished part became whitish.