The Impact of Bacillus Thuringiensis Israelensis (Bti) on Adult and Larvae Black Fly Populations

In the year 2007, the Ministry of Health (MoH) initiated a larviciding program using Bacillus thuringiensis israelensis (Bti) to mitigate the effects of black fly bites. This study was aimed at assessing the impact of Bti on adult and larvae black fly populations. Baseline data was collected prior to Bti application and after application Larva monitoring was done using four different substrates: nylon strips, rocks, and debri. Adult monitoring was carried out by human landing catches. Data analysis included descriptive summaries, t-tests, regression and Analysis of Variance (ANOVA). The analysis also included the assessment of the effect of Bti on adult flies and Larva density on substrates. All the statistical analysis were done at 5% significance level. The results showed statistically significant differences (p <0.001) in populations of black fly before and after Bti application. Larva density was higher before Bti application and adult numbers were also high in that period. After Bti application a decrease in larva density was recorded and this associated with a gradual decrease in adult numbers. Bti had an impact on the larval population in that a decrease in larva population due to larviciding resulted in the decrease of adult population

Hydro-Physicochemical Changes in Domasi River Associated with Outbreak of Blackflies (Diptera; Simuliidae) in Zomba, Malawi

Blackflies impact human and animal health due to their biting nuisance and transmission of Ochocerca volvulus. This study presents an attempt to analyze hydro physicochemical changes associated with outbreak of black flies in Zomba, Malawi. The study compared historical data of hydro physicochemical parameters before (1985-2002) and after (2008) the outbreak to deduce the changes associated with mass occurrence of these flies. Changes in water quality between these two periods were assessed using T-tests. To establish the relationship between the black fly larval densities and water quality parameters data was subjected to both principal component and correlation analysis. Three principal components before the outbreak and two principal components during the outbreak (both dry and wet season) accounted for most of the variation in water quality in this river system. Nutrient load, increases in Total Suspended Solids (TSS) and Total Hardness (TH) were the main factors that had high loadings on these principal components over the years. A significant correlation was established between black fly larval densities and total hardness (r=0.86, p<0.05) as well as total suspended solids (r = 0.755, p<0.02). The potential role of anthropogenic influences on water quality and its cascading effect on black fly population dynamics is discussed

Food security in a perfect storm:Using the ecosystem services framework to increase understanding

Achieving food security in a ‘perfect storm’ scenario is a grand challenge for society. Climate change and an expanding global population act in concert to make global food security even more complex and demanding. As achieving food security and the millennium development goal (MDG) to eradicate hunger influences the attainment of other MDGs, it is imperative that we offer solutions which are complementary and do not oppose one another. Sustainable intensification of agriculture has been proposed as a way to address hunger while also minimizing further environmental impact. However, the desire to raise productivity and yields has historically led to a degraded environment, reduced biodiversity and a reduction in ecosystem services (ES), with the greatest impacts affecting the poor. This paper proposes that the ES framework coupled with a policy response framework, for example Driver-Pressure-State-Impact-Response (DPSIR), can allow food security to be delivered alongside healthy ecosystems, which provide many other valuable services to humankind. Too often, agro-ecosystems have been considered as separate from other natural ecosystems and insufficient attention has been paid to the way in which services can flow to and from the agro-ecosystem to surrounding ecosystems. Highlighting recent research in a large multi-disciplinary project (ASSETS), we illustrate the ES approach to food security using a case study from the Zomba district of Malawi

Urinary schistosomiasis among preschool children in Malengachanzi, Nkhotakota District, Malawi: Prevalence and risk factors

Aim: This study was designed to determine the prevalence of and risk factors for schistosomiasis among a group of preschool children in Malawi. Schistosomiasis burden among preschoolers in Malawi is not well documented in the literature.Methods: This study used field research (in the form of a snail survey), laboratory work (urinalysis and microscopy for parasite identification), and questionnaireguided interviews to determine the prevalence of and risk factors for urinary schistosomiasis among children, aged between 6 and 60 months, in Malengachanzi, Nkhotakota District, Malawi.Results: Urinary schistosomiasis prevalence among preschool children was 13%. Of the factors evaluated, only age (P = 0.027) was statistically significantly associated with urinary schistosomiasis risk. Four-year-old preschool children were five times more likely to contract urinary schistosomiasis than twoyear-old children (odds ratio [OR] = 5.255; 95% confidence interval [CI] = 1.014-27.237; P = 0.048). Increased contact with infested water among older children likely explains much of their increased risk. Infestation was evidenced by the presence of infected Bulinus globosus snails in the water contact points surveyed. Multiple regression analysis showed that visiting water contact sites daily (OR = 0.898, 95% CI = 0.185-4.350, P = 0.894), bathing in these sites (OR = 9.462, 95% CI = 0.036-0.00, P = 0.430) and lack of knowledge, among caregivers, regarding the causes of urinary schistosomiasis (OR = 0.235, 95% CI = 0.005 1.102, P = 0.066) posed statistically insignificant risk increases for preschoolers contracting urinary schistosomiasis.Conclusions: Urinary schistosomiasis was prevalent among preschool children in Malengachanzi, Nkhotakota District. Contact with infested water puts these children and the general population at risk of infection and reinfection. Inclusion of preschool children in treatment programmes should be considered imperative, along with safe treatment guidelines. To prevent infection, the population in the area should be provided with health education and safe alternative water source

The impact of animals on crop yields in Malawian rural villages

It is essential that the net effect of biodiversity on crop yields is determined; particularly in developing nations, where both increasing food security and reducing biodiversity losses are of high importance. This study modelled the abundance of pests, pollinators and pest-control animals and determined their impact on crop yield within agroecosystems in four rural villages in Malawi. Data on the habitat area, survivorship, fecundity, birthing month and effect on crop yield for 14 animal functional groups were collated through a focused meta-analysis. Using this data, models were created to determine the abundance of each functional group using land cover as the sole input variable; with Participatory Rural Appraisals (PRA) utilised to validate the model prediction. Bees, birds and insects always improved crop yield, whereas monkeys, rodents and large herbivores always result in losses. Three out of four villages experienced a net benefit to crop yield from the animal biodiversity present. We conclude that models derived from meta-analyses appear useful for broadly predicting the local-scale abundance of functional groups and their qualitative impact on crop yield. However, long-term field observations should be conducted to ensure that the PRA values in this study correlate with direct observation

A watershed-based adaptive knowledge system for developing ecosystem stakeholder partnerships

This study proposes a Watershed-based Adaptive Knowledge System (WAKES) to consistently coordinate multiple stakeholders in developing sustainable partnerships for ecosystem management. WAKES is extended from the institutional mechanism of Payments for Improving Ecosystem Services at the Watershed-scale (PIES-W). PIES-W is designed relating to the governance of ecosystem services fl ows focused on a lake as a resource stock connecting its infl owing and outfl owing rivers within its watershed. It explicitly realizes the values of conservation services provided by private land managers and incorporates their activities into the public organizing framework for ecosystem management. It implicitly extends the “upstream-to-downstream” organizing perspective to a broader vision of viewing the ecosystems as comprised of both “watershed landscapes” and “marine landscapes”. Extended from PIES-W, WAKES specifies two corresponding feedback: Framework I and II. Framework I is a relationship matrix comprised of three input-output structures of primary governance factors intersecting three subsystems of a watershed with regard to ecosystem services and human stakeholders. Framework II is the Stakeholder-and-Information structure channeling five types of information among four stakeholder groups in order to enable the feedbacks mechanism of Framework I. WAKES identifies the rationales behind three fundamental information transformations, illustrated with the Transboundary Diagnostic Analysis and the Strategic Action Program of the Bermejo River Binational Basin. These include (1) translating scientific knowledge into public information within the Function-and-Service structure corresponding to the ecological subsystem, (2) incorporating public perceptions into political will within the Service- and- Value structure corresponding to the economic subsystem, and (3) integrating scientific knowledge, public perceptions and political will into management options within the Value-and-Stakeholder structure corresponding to the social subsystem. This study seeks to share a vision of social adaptation for a global sustainable future through developing a network to adopt contributions from and forming partnerships among all ecosystem stakeholders