Oviposition Behavior of Culex quinquefasciatus and Anopheles coluzzii Females According to the Ovitrap Color and Presence of Fertilizer in Breeding Sites

Abstract

Malaria and lymphatic filariasis are still important public health problems in Cameroon and in most part of sub-Saharan Africa. However there is still not enough informations on the bionomic and oviposition behaviour of their respectives vectors. The present study assesses the influence of color and organics pollutants presence on Culex and Anopheles coluzzii females oviposition behaviour. Laboratory experiments using Culex quinquefasciatus and Anopheles coluzzii laboratory colonies were conducted. Gravid females were offered cups of different colors (red, green, yellow, black, purple and white) with water for oviposition. Experiments were also conducted with cups containing different concentration of NPK fertilizers (1%, 0.75%, 0.5% and 0%). The influence of NPK fertilizer on the larval development time was also assessed. Cx quinquefasciatus and Anopheles coluzzii gravids females were found to be attracted by dark colors over 50% of eggs were laid in cups of black, red or green colors. The experiment was conducted with the mother and the F1 and F2 generations and similar oviposition preference were registered. When mosquitoes were offered cups containing different concentration of NPK for oviposition it appeared that females of the two species prefer laying their eggs in low concentration of NPK. Rearing of larvae in water containing NPK fertilizers was found to accelerate the larval development time of Culex quinquefasciaus but not of Anopheles coluzzii. The study indicated that several factors could be influencing vector bionomic and need further understanding to improve the fight against vector populations.