Toxic effect of botanical extract based insecticide on Nilaparvata Lugens, Brown Planthopper

Abstract

The invasion of the Nilaparvata lugens, brown planthopper (BPH) in paddy fields has led the uses of excessive chemical insecticides due to its effectiveness. However excessive applications has contribute several negative effects in the paddy field not only to the environmental but also to the farmers as well as non-targeting organism. As an alternative natural pesticides from chili and ginger extracts have been studied. The extract have applied to the BPH thus BPH were collected and breeded prior to optimization the biopesticide application condition on the BPH and the chili and ginger effect on the BPH in term of chemical and physical characterization were investigated. The chemical compounds such as capcaisin, gingerol and shogaol have been proved to give a pungent effect towards BPH which consequently resulted in high mortality. The optimization of chili and ginger extract as a natural pesticide against the BPH were discovered through the analysis conducted by central composite design (CCD). From the experiment, it shown that BPH were died at 90.00% at optimum condition of 40.00% of extract concentration, time exposure at 48.00h and temperature at 30 0C. Then, it also observed that BPH were develop wings after exposure to the extract mixture while some were died. Through HPLC analysis proved that gingerol was presented at peaks at 11.046 min while capsaicin was comfirmed at 4.502 min. Thus, it has been proved that the gingerol and capsaicin were present in chili and ginger extract. Repellency analysis have shown positive results where the repel BPH from the paddy. This is due to the pungent odor contributed from compound of gingerol, shogaol and capsaicin presented in the mixture. Meanwhile, in contact toxicity have successfully give 100% of mortality of BPH due to inability to breathe. Microscope analysis have shown the level of deformities becomes complex when concentration of chili and ginger extract are increased.