,  , Silver-grey or dark brown scaring, or dark brown discolored damages caused by the yellow tea thrip, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae) have occurred on citrus fruits cultivated in the open field in east-south area orchards of Jeju Island since 2007. The weekly population of yellow tea thrips adults caught with a yellow sticky trap increased gradually from early May and peaked in late August, 2009. In 2010 and 2011, the most population was in early October. The yellow tea thrips of some species usually dominated from July in open citrus fields, and seven generations, at least, had occurred from May to late October 2009 by a yellow sticky trap survey. In 2009, S. dorsalis larva were observed from July and with peaks from late August to mid September and early October on citrus fruits. The damage symptoms appeared in the mid September. In 2011, the population peaks were in early July and late September, and the symptoms increased continually from mid July to late October. The symptoms were silver-scars or initial dark discolorations and then gradually changed to dark-brown discolorations or dark-brown scars. The percent of damaged fruits were 0.9%, 0.4%, 0.8% and 2.7% in 2008, 2009, 2010 and 2011, respectively, by survey in 64 typical orchards in Jeju Island. We are the first to report symptoms of the yellow tea thrip (Scirtothrips dotsalis) on citrus fruits.