Abstract/Overview Most odour baits designed to attract host-seeking mosquitoes contain carbon dioxide (CO2), which enhances trap catches, given its role as a mosquito flight activator. However, the use of CO2 is expensive and logistically demanding for prolonged area-wide use. METHODS: This study explored the possibility of replacing organically-produced CO2 with 2-butanone in odour blends targeting host-seeking malaria mosquitoes. During semi-field and field experiments MM-X traps were b...
Abstract/Overview Monitoring of malaria vector populations provides information about disease transmission risk, as well as measures of the effectiveness of vector control. The Suna trap is introduced and evaluated with regard to its potential as a new, standardized, odour-baited tool for mosquito monitoring and control. METHODS Dual-choice experiments with female Anopheles gambiae sensu lato in a laboratory room and semi-field enclosure, were used to compare catch rates of odour-baited S...
Abstract Natural disturbances and human activities are significantly affecting indigenous trees species in forests. Warburgia ugandensis is a plant highly valued for its medicinal properties, timber and fuel among other uses. Many rural communities use it as a remedy for a number of ailments. Investigations into the value of its chemical content reveal that it has antibiotic, antifungal, anti inflammatory and antiseptic effects. W. ugandensis has been rated as the second highest medicinal pl...
Abstract Phytoplankton biodiversity studies in Kenya's standing waters were carried out between 2001 and 2003. Toxin producing cyanobacteria were recorded in twelve water bodies. Microcystis and Anabaena were the most common species in freshwaters while Anabaena and Anabaenopsis were common in alkaline saline lakes. Seven lakes with cyanobacteria blooms and a hot spring had detectable levels of microcystins and anatoxin-a. Cell bound microcystins (LR equivalents) concentration ranged from 1....
Abstract Increasing degradation of the water quality, caused by overuse and salinization, leads to considerable changes of the phytoplankton composition in Kenyan Rift Valley lakes. Exemplarily, the phytoplankton communities and biomasses of deteriorating freshwater Lake Naivasha and salinizing Lake Oloidien were studied between 2001 and 2005, accompanied by physico-chemical measurements (pH, total phosphorus and nitrogen, alkalinity, conductivity). Over the last three decades, the ecology o...
Abstract Molecular markers have effectively been applied to study genetic diversity and as markers of particular traits. This study assessed the diversity of twenty four (24) coffee genotypes using 10 Random Amplified Polymorphic DNA (RAPD) primers and 2 microsatellites (M24 and Sat 235). A total of 35 polymorphic bands were generated by the RAPD primers. The bands were scored for presence (1) and absence (0) of amplified products. The data was subjected to cluster analysis using R statistic...
Abstract Diazinon degrading bacteria were isolated from the soil and gut of fungus cultivating termites Macrotermes michaelseni using MM7 media supplemented with pesticide as the sole source of carbon and energy. The isolates were gram negative rods the isolates from the soil were designated DS2, DS3 and DS5 while from termite gut was designated DT2. 16S rRNA gene sequence analysis showed that diazinon degrading isolate DS2 (from the soil) is closely related to Achromobacter xylosoxidan AF50...
Abstract Changes in carbon and nitrogen cycles in tropical soils affect soil functioning and ecosystem activity. Termites play important roles in carbon and nitrogen cycles, thus determination of levels of such compounds is essential. This study was aimed at determining the levels of various forms of nitrogen, carbon and pH in the guts, soil and nest materials associated with Odontotermes and Macrotermes termite species. Macro- and micro-elements such as potassium, calcium, magnesium, phosph...
Abstract Bemisia tabaci is a widely distributed crop pest affecting the yield of a broad range of agricultural, fiber, vegetableand ornamental crops. It is an extremely polyphagous pest that causes direct damage and can act as a vector ofviral plant diseases. Populations of Bemisia tabaci that are morphologically indistinguishable and with differentbiological traits have been known to exist; they show differences in rates of development, host range, insecticideresistance and virus transmissi...
Abstract In order to reduce parasite-induced mortality, hosts may be involved in mutualistic interactions in which the partner contributes to resistance against the parasite. The pea aphid, Acyrthosiphon pisum Harris (Hemiptera: Aphididae), harbours secondary bacterial endosymbionts, some of which have been reported to confer resistance against aphid parasitoids. Although this resistance often results in death of the developing parasitoid larvae, some parasitoid individuals succeed in develo...
Abstract Invasive Gelechiidae pest species, namely Tuta absoluta, Phthorimaea operculella, Aproaerema simplixella, Sitotroga cerealella, and Pectinophora gossypiella are among the major constraints hampering agricultural economy in Kenya. Infestation levels were determined on respective host crops sampled from different localities and P. operculella recorded the highest infestation of 68.00 ± 4.92% on stored potato. Aproaerema simplixella and T. absoluta accounted for 61.33 ± 5.35% and 51....
Abstract Seagrass and associated blue carbon ecosystems are important carbon sinks, and hence understanding their spatial and temporal variability is vital in appreciating their potential roles in climate change mitigation and adaptation. The Indo-Pacific region has the highest seagrass biodiversity, yet little focus has been made to compare seagrass habitat extent and carbon dynamics with their temperate counterparts. The present study assessed habitat characteristics and seagrass species ...
Abstract Seagrass meadows are considered as global hotspots of blue carbon stocks. However, they suffer global cover loss mainly due to anthropogenic activities. Few is known on the impact of seagrass loss on their blue carbon stocks. This study investigates the impact of seagrass removal on soil organic carbon stocks two years after initial perturbation, and the potential bioturbation activity of co-existing burrowing shrimps in Gazi Bay, Kenya. Seagrass aboveground biomass was removed for ...
Abstract/Overview Gynanisa maja is an edible caterpillar and contributes significantly towards household food security. The linkage between indigenous and scientific knowledge influencing G. maja forage preference is not yet clear, and therefore the study aimed at determining this linkage regarding host preferences for G.maja in western Zambia. A household survey was conducted to determine people’s perception on the most preferred host plants and in order to compare with the laboratory ...
Abstract/Overview Among the factors contributing to food shortage in Africa are lack of appropriate preservation and storage facilities, tropical heat and poor road network for marketing produce. High food spoilage caused by high temperatures of the tropical areas necessitates storage for all householders. Marginal areas of Lake Victoria often suffer protein deficiency due to dependence on narrow base sources of protein, most of which get spoilt during storage. The lake region is endowed ...