What is the limitation of chemical products in fly management?

The statement that chemical products can reduce adult fly numbers temporarily is accurate because most insecticides act quickly upon contact or ingestion, killing adult flies that come into contact with these products. However, these effects are often short-lived, as they do not address the underlying populations of flies, particularly the eggs and larvae, which can continue to develop in the environment. This highlights the limitation of relying solely on chemicals for fly management. A comprehensive pest management strategy typically involves using multiple control methods, including sanitation practices and habitat modification, to mitigate fly populations more effectively over time.

In contrast, the other options suggest absolute results or limited effectiveness that do not accurately reflect the capabilities of chemical treatments in fly management. For instance, the notion that chemicals eradicate all fly populations is overly simplistic, as their effects are usually temporary and can only reduce populations not eliminate them entirely. Additionally, asserting that chemicals only affect developing maggots ignores the fact that many products are effective against adult flies as well. Finally, the idea that chemicals create long-lasting barriers is misleading; most insecticides do not provide prolonged protection, as they break down or are washed away, allowing new flies to reinvade the area.