Culex quinquefasciatus mosquito feeding. Lateral view of a C. quinquefasciatus mosquito on human skin, using its proboscis to obtain a blood meal. Blood is seen in its swollen abdomen. C. quinquefasciatus is one of the many arthropodal vectors responsible for spreading the arboviral encephalitis, West Nile Virus (WNV), to human beings through their bite. West Nile Virus causes symptoms ranging from a mild fever to often fatal effects such as spontaneous bleeding of the skin and circulatory failure.