Insecticide can control the population density or reduce or eliminate harmful insects.

According to the way of action can be divided into: stomach poison, disinfectant, fumigant, internal suction agent, specific insecticide, comprehensive insecticide and so on.

 Stomach Insecticide: the medicine enters the insect body through the insect mouth organ and the digestive system,causes the insect poison to die. Such as: trichlorfon, methyl isomerphosphorus and so on. Used for controlling insect pests of chewing mouthparts (such as ground tiger, Coriander, grasshopper, etc.) Siphon mouthparts (butterflies) and licking mouthparts (flies) pests.

 Contact Insecticide: The insecticide penetrates into the insect body by contacting with the insect body wall (including epidermis, antennae, appendages, feet, wings, etc.), and causes the insect body to be poisoned and die.Such as: pyrethroid insecticides cypermethrin, deltamethrin and so on.Suitable for all kinds of insect pests with mouthparts, but not for insect pests with wax layer and other protection on body wall (such as scale insect).

 Fumigant: can vaporize into poisonous gas under normal temperature and pressure, or decompose into poisonous gas, and enter the insect body through the valve and respiratory system of insects, so that the pests will be poisoned and die, and all the insects will be poisoned.

Such as: dichlorvos, aluminum phosphide and so on.Fumigant is commonly used under closed conditions (greenhouse, greenhouse, warehouse).

 Systemics insecticide: inhaled through the leaves, stems, roots, or seeds of the plant and can be transported, retained, or metabolized by the plant to produce more toxic substances.

When the insect stings and sucks the SAP of poisonous plants or bites the poisonous tissue, it will cause death by poisoning.It is mainly used for the control of aphids, planthoppers, stink bugs, etc., and file sucking mouthparts (such as thrips), commonly used for the control of dimegol, imidacloprid, diniformis, etc.In addition, although some insecticide can infiltrate plant body, but cannot be in plant body conduction, call "inside ooze agent".

Specific insecticides: repellent, repellent, decoy, sterile, hormone-like agent, etc. For example, imulose and flufluron died by inhibiting insect chitin synthesis and obstructing their normal ecdysis and metamorphosis.

 Integrated pesticides: The above effects of pesticides are relative. Many insecticides have several functions at once. Under certain application methods, insecticides may play one or several roles. Such insecticides with various insecticidal effects are called comprehensive insecticides. For example, chlorpyrifos has the functions of touch, stomach poison, fumigation and osmosis, which can kill a variety of pests.