chemical insecticide
2.l-roemerine was isolated from tuber of Stephania kwangsiensis and identified, and it was the main active ingredient. l-roemerine had high contact toxicity to brown planthopper, with a LD50 value being 0.0443 μg/female. Contact toxicity of l-roemerine to brown planthopper was 7.48 times that of malathion, the convientional chemical insecticide used for controlling brown planthopper.
4.A nonpersistent chemical, C4H7O4PBr2Cl2, used for mosquito control and as an insecticide against crop pests.
5.A chemical, such as a hormone, a fungicide, or an insecticide, that improves the production of crops.
6.In result the duckling-yellow colour seemed to attract more aphids. As a result of watering for chemicals treatment with desired concentrations,it showed that the chemical rogor 1; 2000-6000 x played a part in systemic insecticide,persistant period lasted up to 12-13 days for watering,and 14 days after treatment,aphid mortality decreased apparently.
