Browsing by Author "Mwatawala, M"

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    Benefit-cost analysis of alternative insect pests management in cashew and mango orchards in Tanzania
    (Pak Publishing Group., 2015) William, J, G.; Hella, J; Lars, E; Offenberg, J; Mwatawala, M; Rwegasira, G
    This study was conducted to determine the financial feasibility of African weaver ants (Oecophylla longinoda) as biological control agents in cashew and mango orchards. It was compared to chemical insecticides and control based on the experimental data in 2012/13 and 2013/14 cropping seasons. Three important discounted financial indicators were used in the study; they are the Net Present Value (NPV), Benefit-Cost Ratio (BCR) and Internal Rate of Return (IRR). Three scenarios concerning the increase of costs and benefits were used. The results of the study showed that all indicators for financial feasibility analysis were positive and accepted in each treatment. In cashew, African weaver ant without feeding indicated highest NPV (TZS 32 640), BCR (2.5:1) and IRR (57%). In mango, conflicting results were observed in feasibility ranking. But African weaver ants without feeding gave highest acceptable NPV of TZS 66 926. The three scenarios showed that setting much higher costs and benefits at five percent the NPV for African weaver ant was highest than other treatments. The findings of this study suggest that African weaver ant without feeding are financially feasible to be adopted and was recommended.
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    The use of light to enhance weaver ant oecophylla longinoda latreille (Hymenoptera: Formicidae) queen catches
    (Sociobiology, 2017) Nene, W; Offenberg, J; Rwegasira, GM; Mwatawala, M
    Production of live weaver ant (Oecophylla longinoda and O. smaragdina) colonies is being developed as the ants provide several ecosystem services in agriculture and as they are used in education and research laboratories. Founding queens needed for colony production can be caught in artificial nests made of live leaves that are curled on trees. In this study we investigated if the catch rate of O. longinoda queens in artificial nests could be improved by attracting queens to trees with a light source (electric torches). We compared catch rates of 50 artificial nests on each of eight citrus trees, four of them with light and four without light. During two mating seasons covering 9 mating flights we caught a total of 178 queens. However, 3.8 times more queens were caught in the trees with light compared to trees without light. We conclude that queen catches can be highly improved by combining artificial nests with an attracting light source.