This number of Mycological Research News features: In this issue; Fungi associated with insects or used for applied biocontrol; Powdery mildews as invasive plant pathogens: new epidemics caused by two North American species in Europe; and Genetic differences among nuclei in arbuscular mycorrhizal fungi.

This theme issue on fungi associated with insects includes ten papers on this topic. These demonstrate that beetle guts are an amazingly rich source of hitherto unknown yeasts, and a zygosporic stage in Harpellales; report the discovery of the first fossil member of Laboulbeniomycetes, and a new Leptographium associated with a bark beetle; examine genetic diversity at the molecular level in Pandora neoaphidis and Beauveria bassiana; identify the genes expressed during conidiation in Metarhizium anisopliae; report a heterothallic mating system in Termitomyces; and describe two low cost methods for the bulk-culturing of Zoophthora radicans and other entomophthoralean fungi.

Other papers introduce a new molecular fingerprinting method for the biofungicidal Pseudozyma flocculosa; reassesses generic concepts in six genera of smut fungi; reveal that Podosphaera tridactyla is paraphyletic; and demonstrate the production of a N-acetylglucosaminidase by a Neotyphodium endophyte inside its grass host.

Fruit body initiation in Pleurotus ostreatus is found to require a sugar moeity, and the localization and expression of ostreolysin during the fruiting process is also examined.

The following new scientific names are introduced: Leptographium koreanum, and Stigmatomyces succini spp. nov.; and Sporisorium fascicularis (syn. Lundquistia fascicularis) comb. nov.