Dispersal of entomopathogenic fungi by collembolans

The aim of the study was to investigate the possibility of and mechanisms involved in dispersal of entomopathogenic fungi by collembolans. It was found that the collembolan species: Folsomia fimetaria, Hypogastrura assimilis and Proisotoma minuta are able to carry viable conidia of the three entomopathogenic fungi: Beauveria bassiana, B. brongniartii and Metarhizium anisopliae both on the cuticle and in the gut. Between 38.3 and 96.1% of the collembolans exposed to sporulating cultures for 1 h gave rise to colonies of the three fungi through conidia carried on the cuticle. After exposure for 1 h in a sphagnum based growth medium containing 107 conidia g−1 wet weight, between 8.2 and 78.8% of the collembolans gave rise to colonies of the three fungi through conidia carried on the cuticle. There were no clear differences between the ability of the three collembolan species to carry conidia on the cuticle, or the ability of the conidia of three fungi to attach to the collembolans. Ingestion by the collembolans had no effect on the viability of conidia of B. bassiana and B. brongniartii, while ingestion of M. anisopliae by F. fimetaria and P. minuta reduced the viability of conidia significantly to 24.3 and 54.0% compared with a germination of 98.8% of the conidia in the uningested control. After feeding on sporulating fungal cultures for 1 h, between 52.2 and 100% of the faecal pellets formed by each of the three collembolan species formed colonies of the three entomopathogenic fungi. While between 6.2 and 70.8% of the faecal pellets produced by each of the three collembolan species exposed to inoculated sphagnum formed colonies of the three entomopathogenic fungi. There were no systematic differences between the abilities of the three collembolan species to disperse the fungi nor between the dispersal rates of the three fungi.