Cadophora margaritata sp. nov. and other fungi associated with the longhorn beetles Anoplophora glabripennis and Saperda carcharias in Finland

Symbiosis with microbes is crucial for survival and development of wood-inhabiting longhorn beetles (Coleoptera: Cerambycidae). Thus, knowledge of the endemic fungal associates of insects would facilitate risk assessment in cases where a new invasive pest occupies the same ecological niche. However, the diversity of fungi associated with insects remains poorly understood. The aim of this study was to investigate fungi associated with the native large poplar longhorn beetle (Saperda carcharias) and the recently introduced Asian longhorn beetle (Anoplophora glabripennis) infesting hardwood trees in Finland. We studied the cultivable fungal associates obtained from Populus tremula colonised by S. carcharias, and Betula pendula and Salix caprea infested by A. glabripennis, and compared these to the samples collected from intact wood material. This study detected a number of plant pathogenic and saprotrophic fungi, and species with known potential for enzymatic degradation of wood components. Phylogenetic analyses of the most commonly encountered fungi isolated from the longhorn beetles revealed an association with fungi residing in the Cadophora-Mollisia species complex. A commonly encountered fungus was Cadophora spadicis, a recently described fungus associated with wood-decay. In addition, a novel species of Cadophora, for which the name Cadophora margaritata sp. nov. is provided, was isolated from the colonised wood.Peer reviewe

Le potentiel enzymatique digestif osidasique de la pyrale du maïs (Ostrinia nubilalis Hbn., Lep., Pyralidae) et ses variations

National audienceInvestigation of the carbohydrase activity of larvae of Ostrinia nubilalis Hbn., showed the preponderance of α-glucosidases and particularly of invertase (70 % hydrolysis in 1 hat optimum pH 6-7.5) and maltase (40 % hydrolysis in 1 h at optimum pH of 5-6). Pectinase showed moderate activity and amylase little activity. There was little change in activity with sex or generation, but great differences appeared between insects reared artificially and insects caught in the field.L’étude des enzymes digestives des larves de la pyrale du maïs révèle la place prépondérante des α-glucosidases, notamment de l’invertase avec 70 p. 100 d’hydrolyse en 1 h à pH optimum 6-7,5 et de la maltase avec 40 p. 100 d’hydrolyse en 1 h à pH optimum 5-6. La pectinase présente une activité moyenne mais l’amylase semble peu efficace. On note peu de variations d’activité suivant le sexe et la génération, mais de fortes différences entre les individus issus d’élevage et les insectes provenant du milieu naturel

Quelques caracteristiques du metabolisme de la flore bacterienne digestive de divers Passalidae xylophages

National audienc