Occurrence and distribution of soil borne entomopathogenic fungi within a single organic agroecosystem

By baiting soil samples with larvae of Galleria mellonella detailed surveys of the occurrences of entomopathogenic fungi were conducted over two consecutive years in the soil of an organically farmed field (17.1 ha) and the associated hedgerow. Samples were collected at specific points (at distances of 25 in) based on Geographical Information Systems (GIS) and sample point coordinates were relocated by Global Positioning System (GPS). In the agricultural field soil Beauveria bassiana was the most common fungus while Paecilomyces fumosoroseus was most common in soil from the hedgerow. Significant clustering of B. bassiana in the agricultural field was found in one of the two years. High and low densities of B. bassiana were subsequently confirmed within selected areas by reducing distances between sample points. The results demonstrated the suitability of the sampling method for identifying distribution patterns of soil borne entomopathogenic fungi and the importance of large sample sizes to describe local biodiversity of the fungi in the soil environment. (c) 2005 Elsevier B.V. All rights reserved.