Culex quinquefasciatus mosquito eggs. The eggs of Culex mosquitoes are glued together side-by-side on the water's surface forming a raft, and can number several hundred. The eggs are usually spindle-shaped and measure about 1 millimetre in length. The eggs are ready to hatch after 1 or 2 days depending on the temperature. C. quinquefasciatus is a vector for several disease-causing arboviruses. These include West Nile Virus (WNV), Zika virus and several encephalitis viruses.