How does the pitfall trap help in insect identification?

The pitfall trap is designed specifically to capture insects as they move through the environment, making it a highly effective tool for insect identification. When placed in the ground, these traps are filled with a catching solution, which can be water or a preservative, allowing any insects that fall into it to be collected. As insects navigate their surroundings—whether they are foraging for food, looking for mates, or seeking shelter—some will inadvertently fall into the trap. This method of trapping provides a straightforward way to gather a sample of the insect population in a specific area, allowing for accurate identification based on the captured specimens.

Using a pitfall trap is beneficial because it can capture a range of crawling insects, including those that are difficult to observe directly. The collected specimens can then be analyzed for their characteristics, which is integral in determining their species and roles within the ecosystem. Other options in the question, such as collecting soil nutrients, growing plants, and identifying soil pH levels, do not relate to the pitfall trap's function or purpose in insect identification.