Pesticides can be divided into the following main types according to their mode of action, toxicological effects and sources, which are summarized as follows in combination with authoritative information:
1. Classification by mode of action
Stomach poison: enters the digestive system through pest feeding (such as trichlorfon).
Contact poison: penetrates the epidermis or blocks the spiracles after contacting the insect body (such as pyrethroids).
Fumigant: enters the insect body through the respiratory system in the form of gas (such as methyl bromide).
Systemic pesticide: after being absorbed by the plant, it is transmitted to the whole plant, and the pest is poisoned after feeding (such as dimethoate).
2. Classification by toxicological effects
Nerve poison: interferes with the nervous system of pests (such as DDT, pyrethroids).
Respiratory poison: inhibits the activity of respiratory enzymes (such as hydrocyanic acid).
Physical poison: kills by physical means (such as mineral oil blocking the spiracles).
Specific insecticides: including repellents, attractants, antifeedants, sterilants, etc., which work by interfering with physiological behavior.
3. Classification by source
Inorganic and mineral insecticides: such as calcium arsenate and sodium fluorosilicate, which have been gradually eliminated due to high residues.
Botanical insecticides: such as pyrethrum and derris, which are environmentally friendly but have a single effect.
Organic synthetic insecticides: including organophosphates (chlorpyrifos), carbamates (furadan), etc., which are highly effective but some are highly toxic.
Insect hormones: such as juvenile hormone analogs, which regulate insect growth.
Supplementary explanation:
Pyrethroids (such as deltamethrin) are widely used because of their high efficiency and low toxicity.
Nicotinoids (such as imidacloprid) act on acetylcholine receptors and are effective against piercing-sucking mouthparts pests.
Benzoyl ureas (such as lufenuron) affect molting by inhibiting chitin synthesis and are environmentally friendly agents.
