The sudden emergence of pathogenicity in insect–fungus symbioses threatens naive forest ecosystems

摘要: Invasive symbioses between wood-boring insects and fungi are emerging as a new currently uncontrollable threat to forest ecosystems, well fruit timber industries throughout the world. The bark ambrosia beetles (Curculionidae: Scolytinae Platypodinae) constitute large majority of these pests, accompanied by diverse community fungal symbionts. Increasingly, some invasive shifting from non-pathogenic saprotrophy in native ranges prolific tree-killing invaded ranges, causing significant damage. In this paper, we review current understanding insect–fungus symbioses. We then ask why that evolved saprotrophs, turn into major tree-killers non-native regions. argue purely pathology-centred view guild is not sufficient for explaining lethal encounters exotic symbionts naive trees. Instead, propose several testable hypotheses that, if correct, lead conclusion sudden emergence pathogenicity evolutionary phenomenon with global biogeographical dynamics. To date, evidence suggests virulence often triggered when factors coincide: (i) invasion territories trees, (ii) ability fungus either overcome resistance host or trigger suicidal over-reaction, (iii) an ‘olfactory mismatch’ insect whereby subset live trees perceived dead suitable colonization. suggest individual cases tree mortality caused should no longer be studied separately, but global, biogeographically phylogenetically explicit comparative framework.