What contributed to rising clothes moth populations?

• A. Loss of chlorinated hydrocarbon insecticides
• B. Increased predator populations
• C. Improved sanitation
• D. Use of ultrasonic devices

Answer: (A)

Clothes moth populations rose when persistent chlorinated hydrocarbon insecticides were phased out or restricted. These long-lasting, broad-spectrum chemicals previously kept many pests, including fabric pests, under control. Once they were removed from use, the chemical pressure on moths weakened, allowing their numbers to rebound. Factors like predators increasing, sanitation improving, or ultrasonic devices having any real impact would not explain a population increase; in fact, predators and better sanitation usually help reduce pests, while ultrasonic devices are largely ineffective for moths.