Which of the following is NOT a life stage of mosquitoes?

The life cycle of mosquitoes consists of four distinct stages: egg, larva, pupa, and adult. Each of these stages plays a vital role in the development of the mosquito. The egg stage involves the laying of eggs, often in or near water. The larva stage is characterized by aquatic organisms that feed on organic matter. The pupa stage is a transitional phase in which the larva transforms into an adult mosquito, and finally, the adult stage represents the fully developed mosquito capable of flying and reproducing.

The correct answer highlights that the option referring to both pupa and adult as a single entity is not accurate, as they represent separate and distinct stages in the mosquito life cycle. Thus, it is clear that pupa and adult are two separate life stages, and mentioning them together in this context is misleading.