Studies on the action way of insect growth regulator, buprofezin for the brown planthopper, Nilaparvata lugens Stal:
Bei Yawei, Gu Xiuhui, Chen Huaping and Gao Chunxian (Institute of Plant Protection, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021)
Buprofezin has high activity against nymphs of the brown planthopper (BPH) and has effectively ovicidal action. Buprofezin failed to translocate from root to stem, however, its translocation was significantly effective between stem and leaf. This paper showed that: 1) when 5 instar nymph fed on buprofezin through parafilm for 48h, LC 50 of oral toxicity was 14.04ppm. When 5 instar nymph was painted with chemical on dorsal thorax, its LD 50 WAS 2.60 μg/g. If nymph contact with the drug membranse on filter paper, its LD 50 was 6.19 μg/cm 2 . Results also indicated that buprofezin was effective in killing nymphs through contacting dorsal thorax, tarsus or rostrum(oral). 2) The ovicidal action of buprofezin has two ways: killing new hatching nymphs by contacting, and inhibiting the development of eggs embryo. 3) The chemical translocated from root to stem caused 13.05% nymph morality, however, the motality of nymph reached upto 61.8%～72.8% by translocating from leaf to stem and from stem base (10 cm from water) to stem toph. 4) Buprofezin has obvious vapou action for N. lugens.