Comparative Study on the Effect of Insecticides and Neem Extract to the Thrips and Honey Bee Pollinators of Pomelo Cultivar Tongdee

Abstract

Number of honey bees (Apis mellifera L.) and thrips (Scirtothrips dorsalis Hood) found on pomelo flowers in the open plots and in cages without any insecticide application were two times higher than those in the spray application with phosalone endosulfan and neem extract. Pomelo, cultivar Tongdee, pollinated by honey bees was found to produce numerous fruit sets. In the open pollination and in cages with bees, 54 and 67% fruits were produced respectively while the ones with both insecticides and neem extract applications gave only 44, 34 and 36% fruits respectively. In cage without bees the lowest of 18% fruits set was observed and with percent fruit drop was as high as 61. Percent fruit drop was also noticed to be higher in the groups of insecticide treatments than neem extract treatment. In addition, more symptoms of thrip damage occurred in the untreated groups than in the treated ones.