Which of the following is NOT a method by which a pesticide can have a toxic effect on a pest?

Traps are a method used to control pest populations, but they do not involve the toxic effects of pesticides. Instead, traps typically work by capturing and holding pests, preventing them from causing harm without relying on chemical action. In contrast, ingestion, inhalation, and absorption are traditional pathways through which pesticides can enter a pest's body and exert their toxic effects.

Ingestion occurs when a pest consumes pesticide residues, where the chemicals act internally. Inhalation pertains to pests breathing in pesticide particles or fumes, leading to internal poisoning. Absorption involves the pesticide being taken up through the skin or exoskeleton of the pest, which also results in systemic effects. Thus, traps stand apart from the direct toxic action associated with the other methods listed.