Plasmodium vivax
Plasmodium vivax is a protozoal parasite and a human pathogen. This parasite is the most frequent and widely distributed cause of recurring (Benign tertian) malaria, "P. vivax" is one of the five species of malaria parasites that commonly infect humans. Although it is less virulent than "Plasmodium falciparum", the deadliest of the five human malaria parasites, "P. vivax" malaria infections can lead to severe disease and death, often due to splenomegaly (a pathologically enlarged spleen). "P. vivax" is carried by the female "Anopheles" mosquito; the males do not bite.
Culex quinquefasciatus
The southern house mosquito transmits zoonotic diseases that affect humans and wild and domestic animals, such as lymphatic filariasis, avian malaria, St. Louis encephalitis, Western equine encephalitis, and West Nile fever, and may be a vector of the Zika virus. It causes infection through biting during blood meal. In the southern U.S., it is the primary vector of St. Louis encephalitis virus. In India and Southeast Asia, it is the primary vector of "Wuchereria bancrofti", a nematode that causes lymphatic filariasis. It acts as an intermediate host for the helminth parasite by harbouring the larval stages. It also transmits "Plasmodium relictum", a malarial parasite of birds, and is its principal vector in Hawaii. It is the definitive host for the malarial parasite as it harbours the sexual cycle.