Population distribution of thrips, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae) in rose plant within different plant parameters

Investigation on “population distribution of thrips, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae) in rose plant within different plant parameters” was carried out at University of Agricultural Sciences, Bangalore during 2008. Out of the different plant parameters viz., young shoot, matured shoot, old shoot, unopened bud, calyx opened bud, matured flower, fully opened flower tested to sample thrips population in upper, middle and lower canopies, matured flower and young shoot (r = 0.96 and 0.90, respectively) were most preferred plant parts for the thrips sampling. They served as the best sampling unit. In polyhouse, fully opened flowers had maximum positive relationship (r= 0.94) compared to matured flower (r = 0.92). Regression equation also showed that matured flower and young shoot were the best representative of the thrips density and were reliable sampling unit. Hence, while sampling for thrips, matured flowers are most reliable parameter. However, during non-flowering time, young shoots can be taken for effective thrips count.