Der Einsatz von Trichogramma-Schlupfwespen in Deutschland

The use of Trichogramma egg parasitoids has further increased. T. brassicae, released against the European Corn Borer Ostrinia nubilalis, holds the largest share in Germany with 11,000 hectare. For small-scale fruits crops the commercial use of T. cacoeciae and T. dendrolimi against the Codling Moth (Cydia pomonella) and the Plum Moth (Grapholita funebrana) has been expanded. Trichogramma species are also being offered for controlling the vine moths, Lobesia botrana and Eupoecilia ambiguella on grapevine in homegardens. A strain of T. evanescens is available against cabbage pests, especially noctuids. Research has been conducted on the biological control of Autographa gamma in spinach, as well as of the Pea Moth (Cydia nigricana) and the Leek Moth (Acrolepiopsis assectella) in organic farming. Trichogramma is also important for the biocontrol of exotic pests in greenhouses. These are often polyphagous pests that have been introduced together with ornamental plants, such as Duponchelia fovealis and Clepsis spectrana. The Carnation Tortrix (Cacoecimorpha pronuba) was successfully controlled by Trichogramma in the field. The use of Trichogramma has been further established for the control of storage pests. T. evanescens is used against the Indian Meal moth (Plodia interpunctella) in stored cereal products. Other target pests in storage environments are Ephestia kuehniella and Sitotroga cerealella. In addition, Trichogramma species have been tested for the control of the Common Cloths Moth (Tineola bisselliella) under laboratory conditions. The range of target pests for Trichogramma egg parasitoids has therefore increased considerably in research and commercial applications in Germany.     

Validation of the periodicity of growth zone formation in the otoliths of four fish species from the Upper Zambezi ecoregion,southern Africa

In the Upper Zambezi and Okavango ecoregions, Brycinus lateralis, Hepsetus cuvieri, Schilbe intermedius and Serranochromis macrocephalus are important in subsistence fisheries, while S. intermedius and S. macrocephalus are often caught in commercial catches. Despite their importance, there is little information on their age and growth and age validation. Growth zone deposition rate in otoliths of B. lateralis, H. cuvieri, S. intermedius and S. macrocephalus was validated as annual using edge analysis in this study. Annual deposition of growth zones was corroborated by a fluorochrome marking experiment. Both methods demonstrated that one growth zone was deposited annually. Edge analysis demonstrated that the highest proportion of opaque zones was detected between August and December, most likely as a result of slow growth during lower temperature water during the preceding winter. With growth zone deposition validated as annual, future research should focus on determining the growth, maturity and mortality rates of these species, parameters which are important for their management.     

Intensification or extensification? Factors affecting technology use in peri-urban lowlands along an agro-ecological gradient in West Africa

The paper analyses whether the increased use of lowlands in proximity to urban centres in West Africa is associated with technological intensification or extensification. Technologies are typified in terms of their orientation – land or labour saving – and market dependence for their procurement and reviews the factors driving and modifying their use in lowlands. The factors associated with technology use are analyzed empirically using geo-referenced lowland data around four urban centers along an ecological gradient in Côte d’Ivoire and Mali. The technologies analyzed include both external inputs (fertilizer, pesticide, herbicide, improved varieties) and crop management practices (plot level bunding, rice transplanting and rice direct seeding). Results from binomial logit models highlight the prominent positive and non-linear role of proximity to urban markets for the technological intensification of lowlands – an issue associated with factor scarcities and the transaction costs for procurement and marketing. Technology use in lowlands is also associated with the agro-ecological gradient, lowland development and non-native lowland users. A common thread linking these variables is that they modify resource scarcity and therefore intensification incentives. Lowlands are not always as valuable as they may seem and there may be limited incentives to intensify. Instances of significant lowland cultivation and intensification in the study sites tend to be associated with specific opportunities – driven by market opportunities and modified by seasonal, institutional or development-induced relative land scarcity. Market access is therefore a necessary but not sufficient factor for the technological intensification of lowland use. There is a need for better targeting of development efforts in terms of enabling lowland intensification or extensification as appropriate.     

The occurrence of Echinococcus multilocularis in red foxes in lower Saxony: identification of a high risk area by spatial epidemiological cluster analysis

There is considerable interest in the spatial distribution of Echinococcus multilocularis in red foxes (Vulpes vulpes L.), because this parasite causes the zoonoses of alveolar echinococcosis which is potentially of high fatality rate. High risk areas are known from France, Switzerland and the Swabian Alb in Germany for a long time. In this work, the spatial scan statistic is introduced as an instrument for identification and localisation of high risk areas, so called disease clusters in spatial epidemiology. The use of the spatial scan statistic along with data about the distribution of the parasite in 5365 red foxes in Lower Saxony, that were collected during 1991 to 1997, led to the identification of another high risk area. The relative risk for this disease cluster is approximated by RR = 5.03 (CI0.95(RR) = [4.27; 6.58]) for the period of 1991 to 1994 and by RR = 4.45 (CI0.95(RR) = [3.53; 5.59]) for the period of 1994 to 1997, respectively.     

Vorläufige Untersuchungsergebnisse über die Lebensweise des PappelknospenwicklersSemasia oppressana Tr. und des PappeltriebwicklersSemasia aceriana Dup.

Ohne ZusammenfassungDie vorliegenden Untersuchungen wurden auf Anregung von Herrn Prof. Dr.-Ing. E. Schimitschek und mit Unterstützung der Landesforstverwaltungen Hessen und Schleswig-Holstein durchgeführt.     

Silicon reduces slug feeding on wheat seedlings

Journal of Pest Science - Slugs are a serious pest of cereal crops, and recent emphasis in slug pest management has shifted from solely chemical towards integrated approaches. The objective of the...     

Spatial Assessment of Land Degradation Risk for the Okavango River Catchment,Southern Africa

The Okavango catchment in southern Africa is subject to environmental as well as socio‐economic transformation processes such as population growth and climate change. The degradation of soil and vegetation by deforestation and overgrazing is one of the downsides of this development, reducing the capacity of the land to provide ecosystem functions and services. In this study, climate simulations are brought together with secondary socioeconomic, pedologic and remote‐sensing data in a GIS‐based assessment of the factors commonly associated with land degradation risk. A high resolution overview is provided for decision‐makers and stakeholders in the region by identifying priority intervention areas where a long‐term decline in ecosystem function and land productivity is most likely to occur. The approach combines 19 risk factors into seven individual ratings for topography, landcover, soil, demography, infrastructure, livestock pressure and climate. These ratings are then weighted and combined into an integrated degradation risk index (DRI). The results show that the land degradation risk is quite heterogeneously distributed in the study area and caused by different factors. Three hot‐spots are identified and compared, one of which is in the far northwestern part of the catchment, one around the local center Rundu and one on the outskirts of the Okavango Delta. We conclude that the approach is suitable to give an overview on degradation risk in the study area, although the classification process is a crucial procedure that should be standardized for further research. Copyright © 2015 John Wiley & Sons, Ltd.