Social & Preventive Medicine Dichloro-diphenyl-trichloroethane (DDT) is one of the most widely used insecticide. Which of the following statement is NOT true about DDT? A Pyrethrum has synergistic action B It is a contact poison C Immediately kills the prey D Residual effect lasts for 18 months 💡 Explanation Dichloro-diphenyl-trichloroethane (DDT) is one of the most widely used insecticide. Which of the following statement is NOT true about DDT? ✓ Correct Answer: C. Immediately kills the prey