Browsing by Author "Onen, Hudson"
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Item Biotic and abiotic factors in anopheles gambiae breeding habitats as a potential tool to fight Malaria in central Uganda(Journal of Disease and Global Health, 2019) Odong, Robinson; Onen, Hudson; Chemurot, Moses; Kayondo, JonathanThere is a high risk of malaria infection in Uganda due to availability of conducive conditions in breeding habitats of An. gambiae s.l., the vectors for Plasmodium, the causative agent of malaria. Aim: The aim of this study was to determine whether the abundance and distribution of macro-invertebrates and An. gambiae s.l. are influenced by water physico-chemical parameters. Methods: In this study, habitats were classified as ponds, streams, temporary pools and roadside ditches. From these habitats, electrical conductivity, total dissolved solids, temperature and pH were measured in-situ in the morning and afternoon between October and December 2017. Macro-invertebrates and An. gambiae s.l. larvae were sampled, preserved, morphologically identified and counted. Results: There was a strong association between An. gambiae s.l. with land use, habitat types and water physico-chemical parameters. Baetidae, Coenagrionidae, Aeshnidae, Nepidae, Lymnaeidae and Hirudidae were highly abundant in streams. Notonectidae, Haliplidae and Elmidae were dominant in ponds while Dytiscidae, Culicidae, Chironomidae, Sphaerolichidae and An. gambiae s.l. were abundant in temporary pools. Carabidae were abundant in roadside ditches. Conclusion: Water physico-chemical parameters, land use and habitat types influenced the abundance and distribution of macro-invertebrates including An. gambiae s.l. We recommend that studies should be conducted to establish the mechanisms through which these factors influence abundance and distribution of An. gambiae s.l. and other macro-invertebrates.Item Exploitation Of Locally Available Organic Wastes For Rearing Black Soldier Fly (Hermetia Illucens) Larvae As A Potential Protein Ingredient For Poultry And Fish Feeds In Uganda(Journal of Biology and Nature, 2019) Onen, Hudson; Odong, Robinson; Chemurot, MosesThe animal industry especially aquaculture and poultry sectors contribute greatly to the livelihoods of households in sub-Saharan African countries. The ongoing depletion of fish stocks used as protein source requires substitution with alternative animal sources, e.g. black soldier fly (BSF) larvae, Hermetia illucens. Hence, this study assessed the growth performance of BSF larvae reared on locally and readily available organic wastes. Five organic waste types/substrates (cattle and swine dropping, chicken house rearing waste, decomposing avocado and millet brew wastes) were tested. Randomly selected third larval instar of BSF from each rearing substrate were measured: girth (in cm), length (in cm) and weight (in grams) using a vernier calliper and a weighing scale respectively. The findings indicate that in the 12 weeks period, millet brew wastes produced larvae with the widest girth, longest length and were heaviest, followed by decomposing avocado, waste from chicken rearing house, cattle and swine droppings. In conclusion, the growth performance of BSF larvae was influenced by substrates investigated. We recommend further studies to determine the nutritional composition of BSF larvae raised on each of the substrates investigated in this study.Item Infestation Levels of Some Pests, Predators and Enemies of Honeybee (Apis mellifera L.) in Two Agro-Ecological Zones of Uganda(Journal of Biology and Nature, 2018) Chemurot, Moses; Onen, Hudson; Kasangaki, Patrice; Kityo, Robert; Sande, Eric; De Graaf, Dirk C.Globally, honeybees are threatened by human-mediated factors like pests, diseases and pesticides. In this study, 370 honeybee colonies were surveyed for selected invertebrate and vertebrate pests in wet and dry seasons (December 2014 to September 2015). Observations were made on human activities, apiary characteristics, landscape and land use type. Counts of selected pests were made by carefully opening, smoking hives before physically searching for the target pests. The pests recorded included; rats (Graphiurus sp.), lizards (Agama sp.), small hive beetle (Aethina tumida), wax moth (Galleria mellonella) and ants (Dorylus sp.). Infestation levels of wax moths were significantly higher in wet season (0.6±2.9) than in the dry season (0.0±0.0) (P < 0.01). In addition, there was a significant negative correlation between wax moth infestation level and elevation (rho = - 0.194, n = 161, P = 0.014). Furthermore, wax moths infestation levels varied significantly across apiaries of different dominant vegetation types (P = 0.001). Old farmlands had significantly higher infestation level of pests wax moths, ant and lizard compared to new farmlands and protected areas (P<0.05). The results support locating apiaries in less disturbed habitats to reduce pest infestation.Item Predatory and competitive interaction in Anopheles gambiae sensu lato larval breeding habitats in selected villages of central Uganda(Parasites & vectors, 2021) Onen, Hudson; Odong, Robinson; Chemurot, Moses; Tripet, Frédéric; Kayondo, Jonathan K.Malaria is often persistent in communities surrounded by mosquito breeding habitats. Anopheles gambiae sensu lato exploit a variety of aquatic habitats, but the biotic determinants of its preferences are poorly understood. This study aimed to identify and quantify macroinvertebrates in different habitat types with determined water physico-chemical parameters to establish those preferred by An. gambiae s.l. larvae as well as their predators and competitors. Methods: A field survey was conducted in Kibuye and Kayonjo villages located in the vicinity of the River Sezibwa, north-eastern Uganda to identify Anopheline larval habitats shared by aquatic insects. Habitats were geo-recorded and as streams, ponds, temporary pools and roadside ditches. From October to December 2017, random microhabitats/ quadrats were selected from each habitat type, their water physico-chemical parameters (electrical conductivity, total dissolved solids, temperature and pH) were measured, and they were sampled for macroinvertebrates using standard dippers. All collected arthropod macroinvertebrates were then morphologically identified to family level and enumerated. Results: Principal component analysis showed that the four larval habitat types were characterized by distinct physico-chemical parameter profiles. Ponds and streams had the highest number and diversity of macroinvertebrate insect taxa and sustained few An. gambiae s.l. larvae. Anopheles gambiae s.l. were more common in roadside ditches and particularly abundant in temporary pools which it commonly shared with Dytiscidae (predaceous diving beetles) and Culex spp. Cluster correlation analysis conducted on the abundance of these taxa within quadrats suggested that An. gambiae s.l. and Dytiscidae have the most similar patterns of microhabitat use, followed by Cybaeidae (water spiders). Whilst Culex spp. co-occurred with An. gambiae s.l. in some habitats, there was only partial niche overlap and no clear evidence of competition between the two mosquito taxa. Conclusions: Ponds and streams are habitats that host the largest diversity and abundance of aquatic insect taxa. Anopheles gambiae s.l. larvae distinctively preferred temporary pools and roadside ditches, where they were exposed