Final answer:
Birds that feed on insects in a rainforest sprayed with DDT will likely accumulate the highest levels of the substance due to biomagnification, leading to detrimental effects such as thinning of eggshells and population declines.
Step-by-step explanation:
In a rainforest that has been sprayed with DDT, the species that is likely to accumulate the highest levels of the substance is a) Birds that feed on insects in the rainforest. This is due to a process known as biomagnification, where harmful chemicals like DDT become more concentrated as they move up the food chain. Birds that consume a large number of insects, which are directly exposed to DDT, end up with much greater amounts of DDT in their systems than the insects themselves. This accumulation has been known to cause thinning of eggshells among bird species like eagles and pelicans, making reproduction difficult and leading to population declines.
Neither the large trees in the rainforest canopy, predatory mammals that hunt in the rainforest, nor the insects that are directly exposed to DDT accumulate as much of the substance as the birds that feed on those insects. The issue with DDT highlights the importance of understanding how chemicals can have a profound impact on the environment, leading to degradation of ecosystems.