Which of the following is a common biological control agent?

Ladybugs are a well-known biological control agent primarily because they are natural predators of aphids and other small pest insects that can harm plants. By introducing ladybugs into a garden or agricultural setting, growers can effectively reduce pest populations without resorting to synthetic chemicals. This aligns perfectly with the principles of Integrated Pest Management (IPM), which emphasizes the use of natural predators as a sustainable approach to control pests and promote ecological balance.

In contrast, traps are primarily a mechanical method of controlling pests rather than a biological approach, as they capture rather than utilize living organisms. Fertilizers are used to enhance plant growth and do not play a role in pest control. Pesticides, although they can effectively manage pest populations, rely on chemicals that may pose risks to non-target organisms and the environment, counteracting the holistic goals of IPM. Hence, ladybugs stand out as a prime example of utilizing biological control in pest management strategies.