Pharmacy and insect parts easily penetrate easily poisoned: Pharmacy invading parts of the brain and nerve from the closer, the more rapid intoxication. Instar larvae of different agents to enter at different speeds, the young larvae are just off the wall and through the skin of the larva, the agent easy invasion. In addition larvae before peeling between Luoyang tiger injection, old skin peeling solution (containing various enzymes), not through agents. Thus, when pesticides for toxicity determination, to choose just off the skin off 3-4 instar larvae. Pesticides are mainly used to control agricultural pests and city health pests drugs. Pesticides Virulence: spray. Spray method mock forest in actual prevention situation and design, in order to reduce experimental error Xinxiang except tiger injection, so that each receives the same test insects as possible dose requires a certain pressure sprayer, so the cloud point of the same size, Spray evenly.