What pest management method involves using barriers to prevent pests from entering?

The method that involves using barriers to prevent pests from entering is mechanical control. This approach focuses on physical barriers, such as screens, fences, or traps, that physically block pests from accessing plants or buildings. Mechanical control can effectively reduce pest populations by creating a physical impediment, making it difficult for pests to invade and causing lesser reliance on chemical solutions.

In contrast, chemical control relies on pesticides to manage pest populations, while biological control employs natural predators, parasites, or pathogens to reduce pest numbers. Cultural control involves changing farming practices or environmental conditions to reduce pest establishment, reproduction, and survival. Each of these methods has its own advantages and strategies, but mechanical control is specifically noted for its physical barriers.