Which of the following is a successful predator used for controlling mosquito larvae?

Gambusia affinis, commonly known as the mosquito fish, is a highly effective predator used for controlling mosquito larvae. This small freshwater fish thrives in a variety of aquatic environments and is known for its voracious appetite for mosquito larvae, making it a valuable biological control agent in managing mosquito populations.

The use of Gambusia affinis is beneficial in integrated pest management practices because it provides a sustainable method of control that reduces the need for chemical pesticides. By introducing this fish into water bodies where mosquitoes breed, populations can be kept in check naturally, which also helps to mitigate the risks associated with mosquito-borne diseases.

The other species listed, such as Anopheles gambiae, Culex pipiens, and Culex quinquefasciatus, are actual mosquito species themselves, rather than predators of mosquito larvae. These species play roles in the mosquito population dynamics but do not serve the function of controlling mosquito larvae in the same way that Gambusia affinis does. Thus, it is clear why Gambusia affinis stands out as the appropriate choice for controlling mosquito larvae effectively.