What kind of medicine is the best for prevention and control of older rice?

Chlorpyrifos and aweisan are effective agents to control Chilo suppressalis medinalis, but they are required to be applied at the stage of 1-2 instar larvae of Chilo suppressalis medinalis (during this period, there is no harm to the leaf roll, or at the beginning of rolling the leaf tip), and when the rice leaf roll begins to roll in the field. On the one hand, the larvae of rice leaf roller above the 3rd instar are protected because they are wrapped in rice leaves, on the other hand, they are not sensitive to organophosphorus pesticides such as chlorpyrifos, methamidophos and monocrotophos, and the control effect is poor after spraying. Relatively speaking, the older rice leaf roller larvae are more sensitive to pyrethroids pesticides such as fipronil, hit, propyl fluoride EC and cypermethrin. Pyrethroids pesticides are not suitable to be used in rice. Spray should increase the amount of medicine, add enough water, generally use 50-60 ml of Regent per mu or 12 ml of hits, plus 50 kg of water spray.