Which of the following arthropods can spread pink eye?

Eye gnats are the arthropods responsible for spreading pink eye, or conjunctivitis. These small flies are known to carry bacteria that can infect the eye when they come into contact with it. They tend to thrive in warm, humid environments and are attracted to the moisture produced by the eyes, making them more likely to land on a person's face.

Understanding the behavior and biology of eye gnats is crucial in public health pest control, especially since they can transmit pathogens not just to humans but also to livestock, affecting both community health and agricultural productivity.

In contrast, the other options, such as sand flies, ticks, and cockroaches, are not associated with the transmission of pink eye. Sand flies typically vector diseases like leishmaniasis, while ticks are known for transmitting diseases such as Lyme disease. Cockroaches are considered pests primarily due to their role in contaminating food surfaces and spreading allergens, but they do not transmit pink eye. This distinction highlights the importance of recognizing specific pests in public health efforts to effectively manage and mitigate their associated health risks.