What are contact poisons?

Contact poisons are defined as pesticides that kill pests upon physical contact rather than requiring ingestion for their effectiveness. These types of insecticides act quickly when they come into direct contact with the surface of the pest’s body, penetrating their exoskeleton and causing death through various physiological processes.

This mode of action is advantageous in controlling pests that may be resistant to ingestion-based poisons, as it ensures efficacy even if the pests are not feeding on treated surfaces. Contact poisons are commonly used for immediate knockdown of insect populations, making them an essential tool in integrated pest management strategies.

Considering the other answer options: Ingested poison options do not align with the definition of contact poisons since they require the pest to consume the substance for it to be effective. Soil-absorbed poisons refer to systemic pesticides that are taken up by plants and can be translocated to various parts, rather than acting through surface contact. Gaseous pesticides focus on effects through inhalation and are not relevant when discussing poisons that act through direct contact.