Identification et traits d'histoire de vie d'un fulgoride du genre Pentastiridius (Hemiptera: Cxiidae) adapté à une culture en rotation annuelle

International audienceCixiid planthoppers have been shown to vector phloem-limited prokaryotes associated with plant diseases world-wide. In eastern France, an emerging disease of sugar beet called syndrome basses richesses has been associated with phloem-restricted bacteria transmitted by a cixiid planthopper within the genus Pentastiridius. Early investigation suggested the species being Pentastiridius beieri. On the basis of a morphological and phylogenetic study we report the identification of the planthopper as Pentastiridius leporinus. Furthermore we report some biological traits of the species, which shows a surprising ecological adaptation to an annual cropping rotation sugar beet-winter cereals.Les fulgorides sont connus comme vecteurs de procaryotes dépendants du phloème associés à des maladies végétales mondialement distribuées. Dans l'est de la France, une maladie émergente de la betterave appelée "Syndrome des Basses richesses" a été associée à une bactérie dépendante du phloème transmise par un cixiide du genre Pentastiridius. Une étude préliminaire suggéra le nom de Pentastiridius beieri. Sur la base d'une étude morphologique et phylogénétique nous modifions son identification comme Pentastiridius leporinus. De plus, nous décrivons quelques traits biologiques de l'espèce, qui montre une surprenante adaptation à une rotation annuelle de culture entre betterave et céréale d'hiver

Birth weight of twins: 2. Fetal genetic effect on birth weight

Intraclass correlation coefficients were calculated for the birth weights of twins born at three southeastern Brazilian hospitals, after adjustment of the natural logarithms of these weights for gestational age, its quadratic and cubic terms, sex, and their interactions. The data indicate that fetal genetic effect on birth weight might have the opportunity to be demonstrated by children born to undernourished women. Undernourishment, acting as a selective force, might enhance the existence of genotypes that determine less need of food for normal development.<br>Os coeficientes de correlação intraclasse foram calculados para o peso de gêmeos nascidos em três maternidades do sudeste brasileiro, depois de ajustar os logaritmos naturais desses pesos para a idade gestacional, seus termos quadrático e cúbico, sexo e interações dessas variáveis. Os dados obtidos indicaram que o efeito genético fetal sobre o peso ao nascer teria a oportunidade de ser demonstrado por recém-nascidos de mães subnutridas. A subnutrição, atuando como força seletiva, realçaria a existência de genótipos que determinam menor necessidade nutricional para o desenvolvimento normal

Conservation of grassland leafhoppers: A brief review

The leafhoppers, planthoppers and their allies (collectively known as the Auchenorrhyncha) are presented as a group of insects that are highly appropriate for studying grassland ecology and conservation, evaluating the conservation status of sites and monitoring environmental and habitat change. Semi-natural grasslands typically support dense populations and a wide range of species with diverse ecological strategies. Their numerical dominance in many grasslands means that they have considerable functional significance, both as herbivores and as prey for higher trophic levels. Population and assemblage studies are supported by good ecological knowledge about most species and modern identification keys. Hitherto, most studies have focused on the composition and structure of assemblages and how they are affected by conservation management. However, grasslands support many rare species with small and fragmented populations which deserve conservation attention in their own right, and recent work has started to reflect this. The effects of management on the composition and structure of grassland leafhopper populations and assemblages are described and an assessment is given of the main threats facing individual species and overall diversity. There is a need to synthesise the scattered literature on grassland leafhoppers, to provide a model for how the composition and structure of populations and assemblages respond to major environmental and anthropogenic gradients across large biogeographic areas. Such an analysis could help predict the impact of likely future changes in land use and climate