Grazing of ectomycorrhizae by microarthropods

Abstract

Microarthropods, including Collembola and mites, are a highly diverse and abundant group of soil animals. Previous information on interactions between microarthropods and ectomycorrhizal fungi has been mainly based on mycelium grown in pure culture. Collembola feeding preferences were assessed by offering naturally occurring ECM to the Collembola species Folsomia candida. Some ECM types, including Tricholoma aestuans, Piloderma bicolor and Suillus spraguei, were grazed. Cenococcum geophilum and Lactarius vinaceorufescens were unpalatable. However, fungi forming unpalatable ECM were grazed when not in symbiosis with the host root. To determine levels of ECM grazing occurring in the field, gut contents of a species of Folsomia and a species of Phthiracaridae were assessed molecularly. No ECM fungi were detected. Although the degree to which soil microarthropods graze ECM in the field is still unknown, this work demonstrates that there is a high degree of variation in palatability among ECM formed by different fungal species.