Which method of pesticide application kills pests primarily through touch?

The method of pesticide application that kills pests primarily through touch is contact poisons. Contact poisons are formulated to affect pests when they come into direct contact with the chemical. This means that the pesticide works by adhering to the surface of the insect’s body, penetrating their exoskeletons and entering their system upon contact. This method is effective for a variety of insects, particularly those that are exposed on the surface of plants or materials where the pesticide is applied.

Ingestion refers to pesticides that are taken into the pest’s body through feeding, making them effective only if the pests consume the treated material. Systemic treatment involves the chemical being absorbed by plants and then circulating throughout their tissues; pests succumb to these poisons when they feed on the plant, rather than through direct contact. Fumigation utilizes gaseous insecticides to fill a space, thereby allowing the pesticide to penetrate all areas and kill pests usually by inhalation. Each of these application methods is effective in its own right, but when it comes to killing pests through touch specifically, contact poisons are the key method.