STUDY ON MORPHOLOGY, BIOLOGY OF Thrips palmi AND EFFICIENCY OF DIFFERENT CONCENTRATION OF NEEM LEAF EXTRACT ON DRAGON FRUIT

A study on morphology and biology of Thrips palmi and effect of some insecticides and neem leaf extract on dragon fruit was conducted at Southern Horticultural Research Institute (SOFRI) and the dragon fruit farms at Duong Xuan Hoi village, Chau Thanh district, Long An province from April 2016 to December 2017. The results showed that the adult of Thrips palmi was light yellow, antennae of male had seven segments and eggs were milky white in color. The life cycle of Thrips palmi completed in 14 - 22 days. The lab trial to study efficiency of nine concentrations of neem leaf extract was conducted at Plant Protection Division-SOFRI; the results showed that two treatments of neem leaf extract were highly effective against Thrips palmi with a concentration of 8% (80.83%) and 9% (84.64%) at 7 days after spraying in lab conditions. The results on field trial indicated that neem leaf extract at 8% concentration was 77.91% efficient, which was as effective as Spinetoram, Imidacloprid, and Azadirachtin + Emamectin to control Thrips palmi at field condition. The rate of “ring net” phenomenon of four treatments: Spinetoram, Imidacloprid, Azadirachtin + Emamectin, and Azadirachta indica-neem leaf extract (12.75 - 17.43%) were low and significantly different compared with the control (42.12%).