Breeding Sites of Culex quinquefasciatus (Say) during the Rainy Season in Rural Lowland Rainforest, Rivers State, Nigeria

Breeding sites of Culex quinquefasciatus (Say) were investigated during a World Bank Assisted Project on Integrated Vector Management (IVM) for malaria control at 5 villages (Ipo, Ozuaha, Omanwa, Omademe, Ubima) in the Ikwerre Local Government Area (LGA). The study was in the rainy season, June-September, 2009, in rural lowland rainforest, Rivers State, Nigeria. Sampling was undertaken daily in a randomly selected (100 m x 100 m) grid in each village. Number of Cx. quinquefasciatus (Say) immatures was approximately 6-fold that of An. gambiae s.l. Nearly 80% of Cx. quinquefasciatus immatures were from container-type breeding sites (metal, plastic containers, “calabashes”, tyres) and least from phytotelmata. The differences were significant (FCal=35695636; FTab=39.86; df 1, 1; p<0.01). Plastic containers were the preferred site-type in this category. The container-type breeding sites also yielded the highest number of immatures per breeding site. In the pools breeding site-types, approximately 55% were from puddles and 45% from gutters; the difference was not significant (FCal=334975; FTab=39.86; df 1,1; p>0.01). In the phytotelmata breeding site-types, about 67% of Cx. quinquefasciatus immatures were from depressions on trees; the difference in total numbers among site-types was significant (FCal=2.47x108; FTab=39.86; df 1,1; p<0.01). The container-type breeding sites yielded approximately 90% of immatures at Omanwa, but decreased to 60% at Omademe. In contrast, nearly 70% of immatures were from pools at Ozuaha and 80% from phytotelmata at Ubima. These variations were significant (FCal=4305.94; FTab=39.86; df 1,1; p<0.01). The results indicate that Cx. quinquefasciatus had invaded rural areas and their breeding sites ubiquitous and variable among villages, highlighting the needs for studies locally, prior to larviciding.