Effects of container colour on the oviposition of Culex pipiens complex mosquitoes (Diptera: Culicidae) and indicators of wastewater quality

Abstract

Mosquitoes are important potential vectors for the spread of various diseases. Constructed wetlands (CW) are breeding sites for mosquitoes especially when used to treat sewage water. Sewage water is high in bacteria and organic material but has low oxygen and light levels. This means few mosquito larvae predators can survive but the larvae can feed and their populations grow unchecked. This study investigated the influence of container colour, water dissolved oxygen, electrical conductivity, and temperature on mosquito oviposition and breeding success. Sets of ten black and ten white containers were set up in various locations for a period of 15 days. Water quality measures and egg raft counts were taken from the fifth up to the 15th day. After the 15th day of each trial all larvae (except for the first instar and pupa) were collected and identified. There were more rafts and larvae, and higher temperatures, found in the black containers. The white containers had higher dissolved oxygen levels and lower conductivity levels, which suggests that white containers had a positive effect on dissolved oxygen levels in water. To minimize the breeding of Culex mosquitoes in a CW it is therefore suggested that white containers be used to minimize mosquito breeding