Borers are insect pests that can be most actively controlled by ?

• A. Repellent chemicals
• B. Pheromone traps
• C. Contact insecticides
• D. Systemic insecticides

Answer: (D)

Systemic insecticides are most effective for borers because these pests spend their life feeding inside plant tissue, not on the surface. Surface repellents won’t reach larvae inside stems and don’t kill them once they’re hidden inside the plant. Pheromone traps are used mainly for monitoring or disrupting mating and don’t provide reliable control of borers that live inside the plant. Contact insecticides require direct contact with the insect, which is unlikely when borers are burrowed inside tissues. Systemic insecticides are absorbed by the plant and distributed through its tissues; when borers feed on treated tissue, they ingest the toxin and die. This method provides protection from the inside out, often applied as a soil drench or trunk injection to move the chemical with the plant’s sap.