Final answer:
Hawks are higher in the food chain and are therefore at greater risk of higher pesticide concentrations through biomagnification. Ecosystems with diverse predators experience better natural pest control, reducing the need for pesticides that can harm biodiversity and ecosystem health.
Step-by-step explanation:
The question posed by the student suggests a focus on the bioaccumulation and biomagnification of pesticides in a food chain. Grasshoppers, which feed directly on treated plants, may ingest certain amounts of pesticides. However, hawks, being higher up in the food chain, may consume multiple grasshoppers and other prey, leading to a higher concentration of pesticides in their bodies through the process of biomagnification. Predatory birds like hawks are particularly susceptible to high levels of pesticide due to their position at the top of the food chain. Studies have shown that pesticide use not only affects pests but also harms non-target species like insects, birds, and bats, leading to a negative impact on biodiversity and ecosystem health. For example, the pesticide DDT, known for its persistence in the environment, resulted in eggshell thinning and population declines in birds of prey, such as eagles and pelicans, until its ban in 1972 in the United States.
Promoting and preserving natural predators and their habitats can enhance natural pest control, benefitting both agriculture and the environment while reducing dependency on chemical pesticides. Ecosystems with diverse natural enemies of pests demonstrate more effective pest control compared to those relying on monocultures of pest predators.