55 research outputs found

    Effect of insecticides on foraging behaviour and pollination role of Apis mellifera L. (Hymenoptera: Apidae) on toria (Brassica campestris var. toria) crop

    Get PDF
    The effects of insecticide application on foraging and pollination by honeybees in toria (Brassica campestris var. toria) cultivar RSPT-1 were studied at Jammu (India).Under field conditions the application of betacylfluthrin, betacyfluthrin + imidacloprid and carbaryl resulted in 100% bee mortality within one hour of spraying. After 48 hours, 100% mortality was recorded in all the treatments except malathion (94%). The post-spraying effects of the insecticides were much higher during the first hour after treatment, but after 48 hr there was 100% mortality in all treatments except imidacloprid (43%). Residual effects after spraying were high for flowers sprayed with imidacloprid (76% mortality), demeton-o-methyl, carbaryl, and ethiprole, moderate for betacyfluthrin (49%), betacyfluthrin + imidacloprid, and profenophos, and low for malathion (12%). The residual effect decreases with time and after 96 hours of spraying, the residual effect was reduced in almost all the insecticides. The number of foraging bees were greatly reduced in all treatments 24 hr after spraying, compared to levels before spraying, recovering considerably after 3 days, and normal after 7 days. Open pollination resulted in 1.80 times more yield compared to caged condition and crop pollinated by bees alone. This study suggests that both protective application of insecticides and use of honeybees for pollination are essential for maximum crop yields

    Plantation vs. natural forest: Matrix quality determines pollinator abundance in crop fields

    Get PDF
    In terrestrial ecosystems, ecological processes and patterns within focal patches frequently depend on their matrix. Crop fields (focal patches) are often surrounded by a mosaic of other land-use types (matrix), which may act as habitats for organisms and differ in terms of the immigration activities of organisms to the fields. We examined whether matrix quality affects wild pollinator abundance in crop fields, given that the species (Apis cerana) generally nest in the cavities of natural trees. We examined fields of a pollination-dependent crop surrounded by plantations and natural forests, which comprised the matrix. Our analysis revealed a clear positive effect of the natural forest on the pollinator abundance, but the plantation forest had little effects. These indicate that agricultural patches are influenced by their matrix quality and the resulting crop pollinator abundance, suggesting the importance of matrix management initiatives such as forest restoration surrounding agricultural fields to improve crop production

    A systematic review of rodent pest research in Afro-Malagasy small-holder farming systems: Are we asking the right questions?

    Get PDF
    Rodent pests are especially problematic in terms of agriculture and public health since they can inflict considerable economic damage associated with their abundance, diversity, generalist feeding habits and high reproductive rates. To quantify rodent pest impacts and identify trends in rodent pest research impacting on small-holder agriculture in the Afro-Malagasy region we did a systematic review of research outputs from 1910 to 2015, by developing an a priori defined set of criteria to allow for replication of the review process. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We reviewed 162 publications, and while rodent pest research was spatially distributed across Africa (32 countries, including Madagascar), there was a disparity in number of studies per country with research biased towards four countries (Tanzania [25%], Nigeria [9%], Ethiopia [9%], Kenya [8%]) accounting for 51% of all rodent pest research in the Afro-Malagasy region. There was a disparity in the research themes addressed by Tanzanian publications compared to publications from the rest of the Afro-Malagasy region where research in Tanzania had a much more applied focus (50%) compared to a more basic research approach (92%) in the rest of the Afro-Malagasy region. We found that pest rodents have a significant negative effect on the Afro-Malagasy small-holder farming communities. Crop losses varied between cropping stages, storage and crops and the highest losses occurred during early cropping stages (46% median loss during seedling stage) and the mature stage (15% median loss). There was a scarcity of studies investigating the effectiveness of various management actions on rodent pest damage and population abundance. Our analysis highlights that there are inadequate empirical studies focused on developing sustainable control methods for rodent pests and rodent pests in the Africa-Malagasy context is generally ignored as a research topic

    Prostate carcinoma metastatic to the skin as an extrammamary Paget's disease

    Get PDF
    Aim: The current paper describes a case of prostatic adenocarcinoma metastatic to the skin presenting as an extrammamary Paget's disease, a very rare and poorly characterised morphological entity. We report a case of prostatic carcinoma metastatic to skin showing a pattern of extramammary Paget's disease which has not been clearly illustrated in the literature Case presentation: A 63 year-old man with prostatic adenocarcinoma developed cutaneous metastases after 16 years. The inguinal metastases were sessile and 'keratotic.' The tumour displayed solid, glandular areas as well as a polypoid region suggestive of extramammary Paget's disease were identified.Discussion and conclusions: We review the diagnostic criteria that have led to the correct histopathological diagnosis in this case. A differential diagnosis of the pagetoid spread in the skin and various forms of cutaneous metastases determined by a prostatic adenocarcinoma as well as the role of immunohistochemistry in establishing the prostatic origin are presented in the context of this case. Although, morphologically the cells presented in the skin deposits were not characteristic for adenocarcinoma of prostate, immunohistochemistry for PSA and PSAP suggested a prostatic origin.Virtual Slides: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1395450057455276. © 2012 Petcu et al.; licensee BioMed Central Ltd
    corecore