Which of the following elements is not essential for the cycling of an arthropod-borne disease?

In the context of arthropod-borne diseases, also known as vector-borne diseases, the cycling of the disease typically relies on a specific set of key components. The essential elements required for these diseases include a pathogen (like a virus or bacterium), a vector (often an insect such as a mosquito or tick that transmits the disease), and a susceptible host (an organism that can become infected).

The presence of a predator is not essential for this cycle to occur. While predators may have an ecological role in controlling populations of vectors or hosts, they do not directly contribute to the transmission or cycling of the disease itself. The cycling of an arthropod-borne disease specifically revolves around the interactions between the pathogen, vector, and susceptible hosts, ensuring that the disease can continue to propagate through these core elements. Therefore, the absence of predators does not interfere with the fundamental transmission dynamics of arthropod-borne diseases.