International plant virus epidemiology workshop : resistance to viruses and vectors, temperate and tropical plants

La mouche blanche #Bemisia tabaci (#Homoptera : #Aleyrodidae$) est le seul insecte connu vecteur de la mosaïque africaine du manioc. Des essais aux champs sont en cours en basse Côte d'Ivoire pour étudier l'écologie des populations aux stades immatures sur le manioc. Des données préliminaires sur la vitesse de développement et le taux de mortalité de chaque stade, la distribution à l'intérieur de la plante et l'évolution des populations dans le temps, sont présentées ici. Les mensurations morphomètriques ont révélé qu'on peut distinguer entre les sexes au dernier stade larvaire. (Résumé d'auteur

International plant virus epidemiology workshop : resistance to viruses and vectors, temperate and tropical plants

The whitefly #Bemisia tabaci is a well known vector of African Cassava Mosaic in tropical countries. By using isozyme electrophoresis (esterase patterns) and host-range studies, tow types of #B. tabaci were characterised : one breeding mainly on cassava, the other breeding on all plants other than cassava. Each types shows a different esterase pattern. (Résumé d'auteur

An Assessment of Land Cover and Threats in Important Bird Areas in Africa

Over 1,200 Important Bird Areas (IBAs) have been identified in Africa, each meeting at least one of four objective criteria that identify it as an area of high conservation importance for birds. Despite their biodiversity value, many IBAs are threatened by habitat degradation and a high proportion lack legal protection.We integrate an inventory of these IBAs with remote sensing data to identify patterns that could be used to assess priorities for monitoring and conservation. Land cover composition in IBAs differed significantly from that in buffer zones of the same area immediately surrounding them and was significantly more homogeneous. Agriculture and deforestation were the most prevalent threats to IBAs, particularly in IBAs containing a high proportion of dense forest or shrub. Human population density within IBAs was no lower than that immediately outside IBAs, and was around three times higher than the average for sub-Saharan Africa. However, projected human population growth was lower than the average for sub-Saharan Africa, with the projected increase greatest in IBAs with a high proportional cover of dense forest and mosaic woodland and lowest in IBAs with a higher grassland component.JRC.H.3-Global environement monitorin

Diversity of leaf katydids (Orthoptera: Tettigoniidae: Phaneropterinae) of Dzanga-Ndoki National Park, Central African Republic, with selected records from other African countries.

Forty-four species of Phaneropterinae are recorded from Dzanga-Ndoki National Park in the Central African Republic. Eight species collected within the park are described as new to science: Phlaurocentrum morettoi n. sp., P. paratuberosum n. sp., P. elegans n. sp., Myllocentrum raggei n. sp., Poreuomena sanghensis n. sp., Cestromoecha longicerca n. sp., C. magnicerca n. sp., and Goetia purpurea n. sp. An additional new species from Guinea is described from specimens preserved in the Museo Nacional de Ciencias Naturales of Madrid, Poreuomena huxleyi n. sp. Eurycorypha stylata St\ue5l, 1873 is recorded for the first time from Burkina Faso and Brycoptera lobata Ragge, 1981 from Ivory Coast. The following synonyms are established: Enochletica affinis Bol\uedvar, 1906 is synonymized with Enochletica ostentatrix Karsch, 1896, Poreuomena gladiator Bol\uedvar, 1906 is synonymized with Poreuomena forcipata Sj\uf6stedt, 1902, and Azamia doriae (Griffini, 1906) is synonymized with Azamia biplagiata Bol\uedvar, 1906. In addition, morphological characters of previously unknown females of Phaneroptera maculosa Ragge, 1956 and Eurycorypha canaliculata Karsch, 1890, and males of Myllocentrum stigmosum (Karsch, 1896) and Cestromoecha crassipes (Karsch, 1890) are described. The presence of titillators in four African genera (Gelotopoia, Brycoptera, Phlaurocentrum and Azamia) is recorded for the first time. In the genus Zeuneria, a sub-equally bilobed, dorsally curved, dorso-lateral abdominal appendage is described for the first time. This new structure apparently delimits an abdominal gland of unknown function on the second tergite

Coverage provided by the global protected-area system: Is it enough?

Protected-area targets of 10% of a biome, of a country, or of the planet have often been used in conservation planning. The new World Database on Protected Areas shows that terrestrial protected-area coverage now approaches 12% worldwide. Does this mean that the establishment of new protected areas can cease? This was the core question of the "Building Comprehensive Protected Area Systems" stream of the Fifth World Parks Congress in Durban, South Africa, in 2003. To answer it requires global gap analysis, the subject of the special section of BioScience for which this article serves as an introduction. We also provide an overview of the extraordinary data sets now available to allow global gap analysis and, based on these, an assessment of the degree to which existing protected-area systems represent biodiversity. Coverage varies geographically, but is less than 2% for some bioregions, and more than 12% of 11,633 bird, mammal, amphibian, and turtle species are wholly unrepresented. The global protected-area systems are far from complete

Enhanced performance in fusion plasmas through turbulence suppression by megaelectronvolt ions

© 2022, The Author(s), under exclusive licence to Springer Nature Limited.Alpha particles with energies on the order of megaelectronvolts will be the main source of plasma heating in future magnetic confinement fusion reactors. Instead of heating fuel ions, most of the energy of alpha particles is transferred to electrons in the plasma. Furthermore, alpha particles can also excite Alfvénic instabilities, which were previously considered to be detrimental to the performance of the fusion device. Here we report improved thermal ion confinement in the presence of megaelectronvolts ions and strong fast ion-driven Alfvénic instabilities in recent experiments on the Joint European Torus. Detailed transport analysis of these experiments reveals turbulence suppression through a complex multi-scale mechanism that generates large-scale zonal flows. This holds promise for more economical operation of fusion reactors with dominant alpha particle heating and ultimately cheaper fusion electricity.N