Mycobiota of Dead Ulmus glabra Wood as Breeding Material for the Endangered Rosalia alpina (Coleoptera: Cerambycidae)

The presence in wood of saprotrophic fungi is crucial for xylophagous insects, as they modify its chemical composition, moisture content and structure, and thus govern the survival and growth rate of larvae. Little is known about the mycobiota colonising the breeding material of saproxylic species. This paper focuses on the mycobiota of dead wych elms Ulmus glabra as breeding material for the endangered Rosalia alpina. Fungal isolates from wood fragments of the breeding material were identified using molecular techniques. A total of 24 taxa of wood-decay fungi were found (16 Ascomycota, 6 Basidiomycota, 1 Zygomycota, 1 unidentified) – saprotrophs and facultative parasites, saprotrophic fungi, fungal parasites and tree parasites. Six taxa were isolated from both the surface and deeper layers of the wood, and also from the wood dust and frass left in R. alpina foraging sites: Cladosporium cladosporioides, Cladosporium sp., Hypoxylon macrocarpum, Phaeoacremonium fraxinopennsylvanicum, Sistotrema brinkmannii and Stereum hirsutum. These fungi may be crucial in enabling R. alpina to colonise dead or dying trees and affect its larval development. Ph. fraxinopennsylvanicum, H. macrocarpum and Daldinia childiae are reported for the first time from Poland.