Answer:
See the answer below
Explanation:
<em>In 5 years, the effectiveness of the pesticide would have reduced because the forces of natural selection would continue to act on the population of the insects and ensures that only those that are fit survive and contribute more to the subsequent generations.</em>
Each year the pesticide is administered, those that are not able to adapt to its effects die off, leaving those that posses the pesticide-resistant genes to survive, reproduce, and give birth to offspring that would have inherited the survival gene and become resistant to the pesticide themselves.
Hence, in 5 years, more of the population of the insect would survive the effects of the pesticide leading to a reduction in its effectiveness. The population of the insect is said to have evolved by natural slection according to Darwin.