Pesticide resistance is increased most by

• A. Varying the type and action of the pesticides used
• B. Applying pesticides at known areas of activity
• C. Using the same pesticide in same place over and over
• D. Waiting before reapplying the same class of pesticides

Answer: (C)

Pesticide resistance increases when pests are consistently exposed to the same chemical in the same location, because the individuals naturally tolerant to that product survive and reproduce, passing on resistance traits to the next generation. This constant selection pressure speeds up the shift in the population toward resistance. Rotating pesticides with different modes of action reduces that pressure and makes it harder for the same resistance mechanism to dominate. Using the pesticide only in known areas can improve efficiency but doesn’t address the fundamental selection process across the broader pest population. Waiting before reapplying the same class delays exposure but doesn’t prevent resistance from developing as long as the same product is used repeatedly.