Entomological surveys were conducted to determine the biological and physicochemical parameters influencing mosquito breeding in rock pools on inselbergs in Kaduna State. Available rock pools were searched on the inselbergs fortnightly between June and October, 2013 in 21 settlements distributed in 7 Local Government Areas.This covered theState vegetation from the Guinea Savanna to SudanSavanna.A total of 368 rock pools were sampled for mosquito larvaeusing soup ladle dipper (0.105L) from 269 (69.7%) rock pools harbouring mosquito larvae. Biological (microinvertebrates, macroinvertebrates, macrophytes, algae and vertebrates) and physicochemical (depth, surface area, distances to adjoining pools, temperature, pH, total dissolve solid, electrical conductivity, total suspended solid, turbidity, hardness, dissolve oxygen, biochemical oxygen demand, chemical oxygen demand, phosphate, nitrate and alkalinity) parameters of the pools were determined. Polymerase Chain Reaction was used for the identification of mosquito species of Anopheles gambiaes.s. Of the 31,726 mosquito larvae collected, thirteen species in three mosquito genera(Aedes, Anopheles and Culex) including Ae. vittatus (95.71%),An. arabiensis (0.01%), An. gambiae s.s. (0.1%), An. longipalpis (0.0%), An. pretoriensis (0.0%), An. rufipes (0.02%), Cx. albiventris (0.84%), Cx. horridus (0.33%)Cx. macfiei (0.76%), Cx. perfidiosus (1.65%), Cx. pipiens pipiens (0.44%), Cx. simpsoni (0.0%) and Cx. tigripes (0.0%) bred in rock pools. Aedes vittatuswas the most dominant mosquito encountered in all the 21 sampling locations. PCR–based assay revealed 41.6% amplification of the An. gambiaecomplex sample with 38.9% populations belonging to An.gambiae s.s. whilst the remaining 2.6% were An. arabiensis. Up to 58.4% of the An. gambiae complex could not be identified through PCR even after three runs. ANOVA showed that the abundance of mosquito larvaediffered significantlywith pH of the rock pools (p<0.05). Highly significant difference existed between the abundance of mosquito larvae and total dissolve solid, electrical conductivity and alkalinity of the rock pools (p<0.001). The abundance of mosquito larvae did not differ significantly with depth, surface area, total suspended solid, hardness and turbidity of the rock pools (p>0.05).Principal Component Analysis showed that temperature, electrical conductivity and total dissolve solids were paramount for mosquito breeding in rock pool habitats. Low positive correlation (r = 0.394) existed between dissolve oxygen and abundance of mosquito larvae (p<0.001). Strong positive correlation (r = 1.000) exist between biochemical oxygen demand and the abundance of mosquito larvae (p<0.005). Nitrate (r=0.047) and chemical oxygen demand had low positive correlation (r=0.029) with mosquito abundance. Strong positive correlation (r) existed between macroinvertebrate and mosquito abundance(p<0.001) while microinvertebrates correlated negatively (r) with the abundance of mosquito larvae (p<0.05) in rock pools.Chlorophytes had widespread occurrence while Microcystis spp. had the highest percentage positivity, being the only cyanophyte associated with mosquito larvae (p<0.05) in rock pools. Chlorophytum laxumwas predominant amongst other aquatic macrophytes found with mosquito larvae in rock pools. Epidemiologically, the mosquito species encountered are potential vectors of human and animal diseases, hence rock pools should be inspected to incriminate vectors and be incorporated in mosquito control strategies.
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