Which of the following is a characteristic of key pests?

Key pests are defined as those species that consistently cause economic damage or may disrupt the aesthetic value of a landscape. They are deemed significant because their presence and impact are predictable, leading to regular management interventions to mitigate their effects. This consistent pattern of damage distinguishes them from other pests that may only appear occasionally or may not cause substantial harm.

Other options suggest characteristics that do not accurately define key pests. For example, while it is true that key pests can be harmful, they are not always harmful in every situation or environment, which makes the notion that they "are always harmful" inaccurate. Additionally, those pests that cause occasional damage may not have the persistent impact needed to be classified as key pests. Lastly, the idea that key pests are easy to eliminate does not hold true, as many key pests may require specific and recurrent management strategies due to their resilience and adaptability.