Which factor is described as a pest developing resistance to the pesticide?

Which factor is described as a pest developing resistance to the pesticide?

• A. The pest developed resistance to the pesticide
• B. The LD50 of the pesticide is too low
• C. The rate of product applied was too high
• D. The restricted-entry interval was not followed

Answer: (A)

Resistance happens when a pest population evolves to survive exposure to a pesticide. With repeated use of the same chemical, individuals that naturally tolerate it survive and reproduce, passing those tolerant traits to their offspring. Over time, the population as a whole becomes harder to control with that pesticide, which is exactly what “the pest developed resistance to the pesticide” describes. That makes it the best answer because it directly refers to this evolutionary response. The other factors don’t describe resistance. An LD50 being too low means the pesticide is highly toxic in general, not that the pest is adapting to survive it. If the product rate is too high, you’re dealing with over-application or safety issues, not the pest’s adaptation. If the restricted-entry interval wasn’t followed, that’s a safety and label-compliance problem, not a resistance mechanism.

Resistance happens when a pest population evolves to survive exposure to a pesticide. With repeated use of the same chemical, individuals that naturally tolerate it survive and reproduce, passing those tolerant traits to their offspring. Over time, the population as a whole becomes harder to control with that pesticide, which is exactly what “the pest developed resistance to the pesticide” describes. That makes it the best answer because it directly refers to this evolutionary response.

The other factors don’t describe resistance. An LD50 being too low means the pesticide is highly toxic in general, not that the pest is adapting to survive it. If the product rate is too high, you’re dealing with over-application or safety issues, not the pest’s adaptation. If the restricted-entry interval wasn’t followed, that’s a safety and label-compliance problem, not a resistance mechanism.