64 research outputs found

    Thin Layer chromatographic analyses of pesticides in a soil ecosystem

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    Silica gel 60, silica gel 60 F254, and aluminium oxide as adsorbents were used to investigate their suitability for the analysis and detection of the pesticides: nitrofen, atrazine, diuron, dioxacarb, propoxur, propanil, carbaryl and cypermethrin in soil ecosystem using ethyl acetate, chloroform, dichloromethane and ethyl acetate/chloroform (1:1) as developing solvents. O-tolidine and potassium iodide reagent were used for the detection of the pesticides. Rf values obtained for the pesticides using the silica gel 60-ethyl acetate, silica gel 60 F254-ethyl acetate, silica gel 60-chloroform, silica gel 60 F254-chloroform, silica gel 60 – (1:1) ethyl acetate/chloroform and silica gel 60 F254 – (1:1) ethyl acetate/chloroform systems generally were within the stipulated range of 0.4 –0.8. Rf values obtained for the pesticides using silica gel 60-dichloromethane and silica gel 60 F254-dichloromethane systems were very low except for cypermethrin and nitrofen. Analysis with aluminium oxide coated plates gave a heavy yellow background with the detection reagent making visualization of spots difficult. Aluminium oxide coated plate is, therefore, not recommended when o-tolidine plus potassium iodide is used as detection reagent

    Preliminary Studies on Inherited Sterility for Field Management of Diamondback Moth (Plutella xylostella) (Lepidoptera: Plutellidae) on Crucifers in Ghana

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    The diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae) is the most destructive insect pest of crucifers in Ghana and the world over. It is estimated to cost about USD 1 billion to control annually worldwide. Reliance on chemicals as the sole control measure for diamondback moth has resulted in the development of a myriad ofproblems including resistance, high residue levels on produce, destruction of natural enemies and pest resurgence among others. Inherited sterility in Lepidoptera insects has a potential for suppressing DBM populations. We conducted this study to evaluate the use of the technique to manage the diamond back moth in Ghana. When 3 – 4 day old pupae were treated with 130 Gy and 150 Gy of gamma radiation, 47% and 46% respectively of the male pupae developed as normal adults whiles 40% and 17% respectively of the female pupae developed as normal adults. However, radiation-induced reductions in fecundity and egg viability were expressed in the parental and first filial (F ) generations. Sterility exceeded 1 66% in the treated parental male and 92% in the treated parentalfemale in both treatments as compared with 78% and 95% in treated F male and female, respectively. The sex ratio was 1 skewed in favour of males in the parental progeny. These results indicate the possibility of using inherited sterility for DBM control.Keywords: Diamondback moth Plutella xylostella, irradiation, inherited sterility, F 1 sterility

    The black soldier fly, Hermetia illucens (Diptera: Stratiomyidae): Trapping and culturing of wild colonies in Ghana

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    The larvae of the black soldier fly (BSF), Hermetia illucens L. (Diptera: Stratiomyidae), are promising candidates to be utilized in alternative organic waste management and for fish and livestock feed production. The scalability of this technology in Ghana will depend on a steady source of large numbers of BSF larvae. The objectives of this study were to identify the most attractive organic manure dumps or heaps in the study area for trapping wild BSF egg clutches and assess the effect of local environmental conditions on the trapping and laboratory rearing of BSF. The study compared the number of egg clutch trapped at different microhabitats including piggery, chicken and sheep waste dumps and on a compost heap. The piggery dump waste was the most suitable site for trapping BSF egg clutches. No egg clutch was deposited nearby poultry and sheep waste microhabitats. Results showed no differences in temperature between microhabitats during egg trapping but relative humidity differed between poultry, sheep and compost, however this did not have any effect on egg clutch trapping. No significant differences in temperature and humidity were observed during larval rearing. Significant differences in weight and length of larvae from both piggery and compost sites were observed on days 5 and 10 after egg hatch. A small scale laboratory colony rearing has been successfully established in Ghana. The design of the larval breeding system appears to be suitable for respective up-scaling that could provide sufficient larval quantities for composting organic waste and producing feed components for livestock and fish

    Strip Cropping: A Potential IPM Tool for Reducing Whitefly, Bemisia tabaci Gennadius (Homoptera: Aleyrodidae) Infestations in Cassava

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    Insect pests and diseases are a major limiting factor to cassava production in Africa. The cassava mosaic virus disease (CMVD), caused by cassava mosaic geminiviruses (CMGs) (Geminiviridae: Begomovirus) and transmitted by whitefly, Bemisia tabaci Gennadius, threatens the production of the crop in Africa, causing an estimated annual yield loss of over 1.5 billion US dollars. A 6-month field experiments were conducted to explore the potential of using strip cropping to reduce whitefly infestations in cassava, Manihot esculenta Crantz (Euphorbiaceae). Five rows each of cassava, Jatropha and cotton were grown around a 10-row (1 m row width) × 25 m cassava plots in a randomized complete block design. At weekly intervals, the levels of whiteflies infestations (number of eggs, nymphs and adults) per plot were determined. A significantly lower numbers of immature (egg and nymph) and adult Bemisia tabaci were found in cassava plots surrounded on all sides by five rows of both cotton and Jatropha curcas, clearly demonstrating the potential of strip cropping as a management option for the suppression of Bemisia tabaci populations

    Innovations in market crop waste compost production: Use of black soldier fly larvae and biochar

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    Purpose Compost production technology and use are known among Ghanaians farmers. However, the long composting period averaging three months has had adverse effect on adoption. The black soldier fly (Hermetia illucens) larvae (BSFL) feed voraciously and breaks down organic wastes fast. Addition of rice husk biochar (RHB) neutralises acidity and aerates the compost. Combined application of BSFL and RHB to feedstocks could therefore reduce composting period and improve compost quality. Method Two studies were conducted with market crop waste (MCW) as feedstock. Firstly, feedstocks at two particle sizes (x 10 mm), with and without BSFL were evaluated to determine degradability, chemical content of the degraded residue and to select appropriate feedstock size ideal for composting. Secondly, the selected feedstocks size of between 5 mm and 10 mm were inoculated with or without BSFL and RHB of 0%, 5% 10% and 15% added. Composting trials were conducted in barrels inclined at 30o to facilitate drainage. Physicochemical and biological parameters of feedstock were monitored until maturity. Results Degradability of MCW by BSFL was feedstock specific rather than feedstock size. Inoculation of BSFL and biochar addition reduced composting period from 76 to 45 days. Biochar addition at 15% increased P availability to 1882 mg kg-1 but reduced total N to 10.5 g kg-1. E coli levels decreased in the BSFL-biochar composts to acceptable limits. Conclusion Composting MCW with BSFL and biochar reduced composting period and improved compost quality

    Inovasi Layanan Di UPT Perpustakaan Universitas Pasundan

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    The development of information and communication technologies have a positive impact and significant for the development of libraries. It will be realized when librarians wisely supported stakeholders to capture and utilize information and communication technologies in the management of an innovation in the Library. Innovation does not only provide a solution to the saturation in the works but also, raise the ratings of webometrics colleg

    Global population genetic structure and demographic trajectories of the black soldier fly, Hermetia illucens

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    Background The black soldier fly (Hermetia illucens) is the most promising insect candidate for nutrient-recycling through bioconversion of organic waste into biomass, thereby improving sustainability of protein supplies for animal feed and facilitating transition to a circular economy. Contrary to conventional livestock, genetic resources of farmed insects remain poorly characterised. We present the first comprehensive population genetic characterisation of H. illucens. Based on 15 novel microsatellite markers, we genotyped and analysed 2862 individuals from 150 wild and captive populations originating from 57 countries on seven subcontinents. Results We identified 16 well-distinguished genetic clusters indicating substantial global population structure. The data revealed genetic hotspots in central South America and successive northwards range expansions within the indigenous ranges of the Americas. Colonisations and naturalisations of largely unique genetic profiles occurred on all non-native continents, either preceded by demographically independent founder events from various single sources or involving admixture scenarios. A decisive primarily admixed Polynesian bridgehead population serially colonised the entire Australasian region and its secondarily admixed descendants successively mediated invasions into Africa and Europe. Conversely, captive populations from several continents traced back to a single North American origin and exhibit considerably reduced genetic diversity, although some farmed strains carry distinct genetic signatures. We highlight genetic footprints characteristic of progressing domestication due to increasing socio-economic importance of H. illucens, and ongoing introgression between domesticated strains globally traded for large-scale farming and wild populations in some regions. Conclusions We document the dynamic population genetic history of a cosmopolitan dipteran of South American origin shaped by striking geographic patterns. These reflect both ancient dispersal routes, and stochastic and heterogeneous anthropogenic introductions during the last century leading to pronounced diversification of worldwide structure of H. illucens. Upon the recent advent of its agronomic commercialisation, however, current human-mediated translocations of the black soldier fly largely involve genetically highly uniform domesticated strains, which meanwhile threaten the genetic integrity of differentiated unique local resources through introgression. Our in-depth reconstruction of the contemporary and historical demographic trajectories of H. illucens emphasises benchmarking potential for applied future research on this emerging model of the prospering insect-livestock sector.Peer reviewe

    Types of interventions targeting dietary, physical activity and weight-related outcomes among university students : a systematic review of systematic reviews

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    Belogianni, Katerina - ORCID 0000-0002-3634-7861 https://orcid.org/0000-0002-3634-7861Item previously deposited in Kingston University repository on 17 April 2019 at: http://eprints.kingston.ac.uk/id/eprint/43127Item not available in this repository.A plethora of studies aiming to improve dietary, physical activity (PA), and weight-related (WR) outcomes among university students have been implemented and summarized in a series of systematic reviews, with unclear conclusions regarding their effectiveness. This overview aims to identify systematic reviews and meta-analyses of studies aiming to improve health outcomes in university students, to assess their methodological quality, to identify the different types of interventions used and outcomes assessed, and to estimate their overall effect. Four electronic databases were searched until 19 March, 2018 following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The identified reviews were described and their methodological quality was rated. The studies of reviews were investigated to identify the different types of interventions used and outcomes assessed. Effectiveness was assessed by measuring the overall number of improved outcomes out of the total number of outcomes reported. As a result, 8 reviews were identified targeting food sales (n = 2), dietary (n = 3), PA (n = 1), WR (n = 1), or all outcomes (n = 1). The methodological quality of the reviews was moderate (n = 5) to low (n = 3). In all, the reviews included 122 studies, of which 36 used an environmental, 51 a face-to-face, 30 an e-intervention, and 5 a combined approach. Environmental interventions improved a moderate number of food sales (32 of 61) and dietary intake (22 of 47) outcomes. Face-to-face interventions improved a high number of dietary cognitive outcomes (15 of 18), a moderate number of dietary intake (28 of 65) and WR (11 of 18) outcomes, and a low number of PA behavioral (22 of 69) and cognitive (2 of 14) outcomes. E-interventions improved a high number of dietary cognitive variables (11 of 16) but had a low effect (≤33%) on the other types of outcomes. In conclusion, face-to-face and e-interventions improved cognitive variables toward diet or PA but were less effective in changing actual behaviors. Environmental interventions favorably changed food sales. Face-to-face and e-interventions moderately affected WR outcomes. Future research should focus on long-term studies.http://dx.doi.org/10.1093/advances/nmz027inpressinpres

    Global population genetic structure and demographic trajectories of the black soldier fly, Hermetia illucens

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    Background The black soldier fly (Hermetia illucens) is the most promising insect candidate for nutrient-recycling through bioconversion of organic waste into biomass, thereby improving sustainability of protein supplies for animal feed and facilitating transition to a circular economy. Contrary to conventional livestock, genetic resources of farmed insects remain poorly characterised. We present the first comprehensive population genetic characterisation of H. illucens. Based on 15 novel microsatellite markers, we genotyped and analysed 2862 individuals from 150 wild and captive populations originating from 57 countries on seven subcontinents. Results We identified 16 well-distinguished genetic clusters indicating substantial global population structure. The data revealed genetic hotspots in central South America and successive northwards range expansions within the indigenous ranges of the Americas. Colonisations and naturalisations of largely unique genetic profiles occurred on all non-native continents, either preceded by demographically independent founder events from various single sources or involving admixture scenarios. A decisive primarily admixed Polynesian bridgehead population serially colonised the entire Australasian region and its secondarily admixed descendants successively mediated invasions into Africa and Europe. Conversely, captive populations from several continents traced back to a single North American origin and exhibit considerably reduced genetic diversity, although some farmed strains carry distinct genetic signatures. We highlight genetic footprints characteristic of progressing domestication due to increasing socio-economic importance of H. illucens, and ongoing introgression between domesticated strains globally traded for large-scale farming and wild populations in some regions. Conclusions We document the dynamic population genetic history of a cosmopolitan dipteran of South American origin shaped by striking geographic patterns. These reflect both ancient dispersal routes, and stochastic and heterogeneous anthropogenic introductions during the last century leading to pronounced diversification of worldwide structure of H. illucens. Upon the recent advent of its agronomic commercialisation, however, current human-mediated translocations of the black soldier fly largely involve genetically highly uniform domesticated strains, which meanwhile threaten the genetic integrity of differentiated unique local resources through introgression. Our in-depth reconstruction of the contemporary and historical demographic trajectories of H. illucens emphasises benchmarking potential for applied future research on this emerging model of the prospering insect-livestock sector.Additional co-authors: Santos Rojo, Chrysantus M. Tanga, Rudolf Meier, Clint Rhode, Christine J. Picard, Chris D. Jiggins, Florian Leiber, Jeffery K. Tomberlin, Martin Hasselmann, Wolf U. Blanckenhorn, Martin Kapun & Christoph Sandroc
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