Farmers sprayed leechi trees to suppress populations of scale insects. This also killed the populations of a predatory lacewing that controlled the numbers of scales. Soon the spraying did no good, and the damage to the leechi from the scales was greater than before spraying had occurred. Few predatory lacewings exist in the trees now because

Question

Quizplus · Accepted Answer

The scenario describes a situation where the use of pesticides led to the decline of a predator population that controlled the number of scales, causing the scales population to grow even more. This suggests that the predator was the limiting agent in the population dynamics of scales, and that the scales were more r-selected than the predator. The fact that spraying did no good after some time indicates that the scales evolved resistance to the pesticide, while the predator did not. This points to the idea that the predator was K-selected, which means that it reproduces slowly, investing heavily in each offspring, while the scales were r-selected, which means that they reproduce quickly, with many offspring that are not heavily invested in. Therefore, the best choice is D.

Farmers Sprayed Leechi Trees to Suppress Populations of Scale Insects