Final answer:
Pest population levels trigger control procedures when they surpass an economic threshold, leading to the use of pesticides or ecologically based control measures, with natural predators and parasites providing crucial natural pest control. However, introduced biological control agents can sometimes cause unintended damage to non-target species.
Step-by-step explanation:
Pest population levels trigger control procedures due to the significant impact pests have on agriculture, competing with humans for food resources. When pest populations reach levels that cause economic damage or surpass a certain threshold, it is often necessary to implement control procedures. This control may come in the form of pesticides, which, while effective, may result in resistance in pests, collateral damage to non-target species, and potential health risks for consumers and agricultural workers. Instead, ecologically based control measures are preferred, relying on predators and parasites of pests which provide natural pest control. These biological control tools have proven effective while also protecting surroundings and lowering costs. Biological control agents, whether introduced or naturally occurring in complex landscapes, can significantly reduce pest populations and pesticide use. However, some introduced control agents can have unintended consequences, such as attacking non-target species and even causing extinctions. Integrating natural predator preservation and promotion into pest management strategies is critical for achieving sustainable food production and environmental health.