Carrion Beetles Visiting Pig Carcasses during Early Spring in Urban, Forest and Agricultural Biotopes of Western Europe

Carrion beetles are important in terrestrial ecosystems, consuming dead mammals and promoting the recycling of organic matter into ecosystems. Most forensic studies are focused on succession of Diptera while neglecting Coleoptera. So far, little information is available on carrion beetles postmortem colonization and decomposition process in temperate biogeoclimatic countries. These beetles are however part of the entomofaunal colonization of a dead body. Forensic entomologists need databases concerning the distribution, ecology and phenology of necrophagous insects, including silphids. Forensic entomology uses pig carcasses to surrogate human decomposition and to investigate entomofaunal succession. However, few studies have been conducted in Europe on large carcasses. The work reported here monitored the presence of the carrion beetles (Coleoptera: Silphidae) on decaying pig carcasses in three selected biotopes (forest, crop field, urban site) at the beginning of spring. Seven species of Silphidae were recorded: Nicrophorus humator (Gleditsch), Nicrophorus vespillo (L.), Nicrophorus vespilloides (Herbst), Necrodes littoralis L., Oiceoptoma thoracica L., Thanatophilus sinuatus (Fabricius), Thanatophilus rugosus (L.). All of these species were caught in the forest biotope, and all but O. thoracica were caught in the agricultural biotope. No silphids were caught in the urban site

Spatial-resolved analysis of histological and biochemical alterations induced by water-soaking in melon fruit.

Water-soaking, a physiological disorder characterised by a glassy texture of the flesh, depreciates greatly the commercial quality of early-season Charentais cantaloupe melons (Cucumis melo L. cv. Talma). Although it is accepted that the genotype and a number of physiological and environmental factors play a role in the development of the syndrome, the intimate mechanisms responsible for water-soaking remain unknown. We report here on an integrated study of the development of water-soaking in fruit. Using nuclear magnetic resonance (NMR) imaging, we have shown that water mobility increased in the diseased tissues. Alteration of the cell wall and the presence of large intercellular spaces were correlated with a severe depletion of cell wall calcium. Water-soaking developed during the late stages of fruit ripening, but no correlation was found with ethylene biosynthesis. Thus, fruits in which ethylene action was blocked by 1-methylcyclopropene remained sensitive to water-soaking. Moreover, the expression of two genes encoding key enzymes in ethylene biosynthesis remained unchanged in response to water-soaking. The major changes observed concerned a protein implicated in calcium signalling processes. While the amount of total calmodulin, the ubiquitous calcium binding protein, was not modified, a particular calmodulin-binding protein (CaM-BP) was absent in water-soaked but not in sound mature tissues. This CaM-BP may be a marker or a determinant of this physiological disorder

Apport de metaux par voie atmospherique a la Mediterranee occidentale

Available at INIST (FR), Document Supply Service, under shelf-number : RP 185 (3098) / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc

Seasonal variations in the diet and food selection of the Algerian hedgehog Atelerix algirus

International audienceThe Algerian hedgehog Atelerix algirus is an insectivorous species. However, the exact composition of its naturaldiet remains largely undetermined, especially in relation to seasonal variations in food availability. From Marchto November, we simultaneously analysed the composition of 180 hedgehog faecal samples and food availabilityin the Soumman Valley, Algeria to assess food selection in this species. The faeces contained 196 differentprey species, of which 92% belonged to the class Insecta. The highest prey species diversity was found in theColeoptera order (100 species recorded) and the highest species occurrence was found in Hymenoptera (65% of theprey items, mainly represented by the harvester ant Messor barbarus, a crop-ravaging species). This study showsthat the Algerian hedgehog is mainly a generalist species with a diet that is strongly linked to food availability.However, seasonal variations were observed in prey selection, and a notable shift in food preference was observedduring autumn. The exact nature of these changes in feeding behaviour remains to be investigated, notably inrelation to changes in energy requirements of this species before hibernation, in terms of quantity and/or quality