How do contact insecticides work?

How do contact insecticides work?

• A. They kill pests that touch them
• B. They must be eaten
• C. They only affect larvae
• D. They require sunlight to activate

Answer: (A)

Contact insecticides kill pests when they touch the treated surface. The chemical is applied to the plant parts or the soil so any insect that crawls over it picks up enough of the product to be killed or knocked down. They don’t need to be eaten, and some products act quickly on contact, with residues continuing to kill any insect that comes into contact later. Because effectiveness relies on contact, thorough coverage is essential and the residual activity is often shorter than with systemic products. This approach is useful for immediate control on ornamentals and turf, but you must consider coverage and potential effects on non-target organisms.

Contact insecticides kill pests when they touch the treated surface. The chemical is applied to the plant parts or the soil so any insect that crawls over it picks up enough of the product to be killed or knocked down. They don’t need to be eaten, and some products act quickly on contact, with residues continuing to kill any insect that comes into contact later. Because effectiveness relies on contact, thorough coverage is essential and the residual activity is often shorter than with systemic products. This approach is useful for immediate control on ornamentals and turf, but you must consider coverage and potential effects on non-target organisms.