What is an effective physical barrier used in pest control?

An effective physical barrier used in pest control is row covers to protect plants from insects. Row covers are lightweight fabric materials that are placed over crops to create a protective barrier against various pests, such as insects. They allow light, air, and moisture to reach the plants while preventing pests from making direct contact, reducing the risk of infestations. This method is particularly useful in the early stages of plant growth or to protect sensitive crops during certain periods, such as when pests are most active.

In contrast, traps typically capture pests, but they do not provide a protective barrier around the plants. Insecticides are chemical treatments aimed at killing pests but do not create a physical separation between the plants and the pests. Biological controls involve the use of natural predators or parasites to manage pest populations, but like insecticides, they do not serve as a physical barrier. Hence, row covers are specifically designed to create a physical barrier, making them the appropriate choice in this context.