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

Role of the gut microbiome in mediating standard metabolic rate after dietary shifts in the viviparous cockroach, Diploptera punctata

Diet may be a significant determinant of insect gut microbiome composition. However, the extent to which dietary shifts shape both the composition and relevant functions of insect gut microbiomes, and ultimately impact host energy balance (i.e. metabolic phenotype), is not well understood. We investigated the impacts of diet switching on Diploptera punctata females maintained on a dog food (DF) diet relative to those fed a comparatively sub-optimal cellulose-amended dog food (CADF) diet for 4 weeks. After this period, dietary shift resulted in a significantly higher average mass-specific standard metabolic rate (SMR) in CADF-fed females compared with DF-fed females. We also uncovered significant 13C-enrichment in DF-fed insect samples relative to CADF-fed insect samples and lowered bacterial essential amino acid (EAA) provisioning in CADF-fed samples. Differences in SMR and EAA provisioning were not accompanied by significant differences in overall microbiome composition between the two groups. However, cellulolytic and nitrogen-fixing bacterial families dominant in wild omnivorous cockroaches and wood-feeding termites were significantly enriched in CADF-fed females than in DF-fed females, at the end of the study. We propose that these changes in microbiome composition after dietary shifts are associated with changes in EAA provisioning and possibly SMR. Further studies are needed to comprehensively understand the relative importance of gut microbial functions among the complexity of factors known to underscore SMR responses in insects under varying dietary conditions. © 2020. Published by The Company of Biologists Ltd.Introduction Materials and methods - Insect rearing and study layout - Measurement of standard metabolic rate - DNA extraction and gut bacterial load determination - Amplicon generation, processing and analyses - Assessment of microbial EEA provisioning - Statistical analyses Results - Effects of diet on body mass, gut mass, bacterial 16S rRNA copy number and mass-specific SMR - Effect of diet on microbiome composition - Gut microbial EAA provisioning Discussion Conclusion

Trees and Insects Have Microbiomes: Consequences for Forest Health and Management

Purpose of Review Forest research has shown for a long time that microorganisms influence tree-insect interactions, but the complexity of microbial communities, as well as the holobiont nature of both trees and insect herbivores, has only recently been taken fully into account by forest entomologists and ecologists. In this article, we review recent findings on the effects of tree-insect-microbiome interactions on the health of tree individuals and discuss whether and how knowledge about tree and insect microbiomes could be integrated into forest health management strategies. We then examine the effects tree-insect-microbiome interactions on forest biodiversity and regeneration, highlighting gaps in our knowledge at the ecosystem scale. Recent Findings Multiple studies show that herbivore damage in forest ecosystems is clearly influenced by tripartite interactions between trees, insects and their microbiomes. Recent research on the plant microbiome indicates that microbiomes of planted trees could be managed at several stages of production, from seed orchards to mature forests, to improve the resistance of forest plantations to insect pests. Therefore, the tree microbiome could potentially be fully integrated into forest health management strategies. To achieve this aim, future studies will have to combine, as has long been done in forest research, holistic goals with reductionist approaches. Efforts should be made to improve our understanding of how microbial fluxes between trees and insects determine the health of forest ecosystems, and to decipher the underlying mechanisms, through the development of experimental systems in which microbial communities can be manipulated. Knowledge about tree-insect-microbiome interactions should then be integrated into spatial models of forest dynamics to move from small-scale mechanisms to forest ecosystem-scale predictions.CEnter of the study of Biodiversity in AmazoniaCOntinental To coastal Ecosystems: evolution, adaptability and governanceBiosurveillance Next-Gen des changements dans la structure et le fonctionnement des écosystèmesHOlistic Management of Emerging forest pests and Diseases,Role of endosymbiotic bacteria in the long-term evolution of a diverse and globally-distributed aphid genus: a Phylogenomic Analysi