![]() Observations on seasonal variations in onchocerciasis transmission by Simulium damnosum sensu lato were made in a study carried out in Kwa Falls, Aningeje in Akamkpa LGA (a typical forest area) of Cross River State, Nigeria. damnosum were significantly higher than the other sites. Water velocity of the breeding sites of S. Water temperature and pH were not significant (p>0.05) while dissolved oxygen and In some of these breeding sites included S. damnosum complex, other Simulium (though not vectors of human onchocerciasis) that were found breeding Three cytospecies of the complex were breeding in the study sites (S. State), Ibii (Umulolo), Imo, Ibii (Aku), Ibu, Ugbi and Iyi-aka) in Imo State Idodo (in Enugu State and Oturkpo (in Benue These breeding sites were positive for pre-imaginal stages of S.damnosum complex: Atan and Akpan-Ikpong (in Cross River ![]() states in the zone: Akwa Ibom, Cross River, Imo, Abia, Enugu, Ebonyi, and Benue. ![]() A total of 29 sites were prospected for immature stages of Simulium in seven V>Entomological studies were undertaken in the primary health Zone A of Nigeria to ascertain the distribution and ecology ofīreeding sites of Simulium damnosuim complex. The Canonical correspondence analyses (CCA) showed that most species had a trend towards altitude, canopy cover, riparian vegetation and water velocity.Ĭopyright © 2015. Principal component analysis (PCA) indicated that at least three principal components have eigen values >1.0 and accounted for 93.5% of the total variability of ecological factors among sampling sites. The Shannon index and number of taxa in the cold season were higher than those in the rainy and hot seasons. asakoae (14.8%), were the three most abundant species. The most frequently found species from all sites were Simulium asakoae (100%) followed by Simulium yuphae (83.3%), and Simulium chiangdaoense, Simulium gombakense, Simulium phahompokense, Simulium fruticosum, Simulium maeaiense and Simulium fenestratum (66.6%). Monthly collections from the six sites yielded 5475 last-instar larvae, belonging to 29 black fly species. The water temperature, water pH, conductivity, total dissolved solids (TDS), salt, water velocity, stream width and depth, streambed particle sizes, riparian vegetation, and canopy cover were recorded from each site. Larvae were collected from six fixed-stream sites in relation to altitude gradients from May 2011 to April 2013. ![]() This is the first study on the seasonal biodiversity of black flies and evaluation of ecological factors influencing their distribution at Doi Pha Hom Pok National Park, northern Thailand. The seasonal species richness was highest in the dry season in all the streams sampled except Ibe stream. There was statistical significant difference (p < 0.001) between the rainy season and dry season in the abundance of immature Simulium species. The Shannon biodiversity index was higher in the dry season than the rainy season, with Kwa falls having the highest 1.593 then a decline in Ojuk stream (1.5772), Ibe stream (1.5655) and Mankor stream (1.562). There was significantly higher collection of Simulium larvae and pupae in the dry season in all except Ibe stream. Submerged weeds showed the highest colonization of immature Simulium species compared to submerged rock surfaces, submerged decayed wood and submerged dead leaves. Of the one thousand one hundred (1,100) immature Simulium species collected between November 2014 and October 2015, 780 (70.91%) and 320 (29.09%) were Simulium larvae and pupae respectively. Larvae and pupae collected were identified as Simulium medusaeforme, S. ![]() A survey of the distribution and abundance of immature Simulium species was carried out in four streams of Oban, Akamkpa Local Government Area of Cross River State, Nigeria. ![]()
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