Sampling and occurrence of entomopathogenic fungi and nematodes in UK soils

Abstract

The occurrence of entomopathogenic fungi and nematodes was measured in samples of soil collected from cultivated and uncultivated habitats in Warwickshire, UK. Fungi and nematodes were isolated from the samples of soil by ''baiting'' with larvae of the wax moth, Galleria mellonella (Lepidoptera: Pyralidae). Following two pilot experiments, a main study was done using soil collected from an arable field, a network of hawthorn hedges and four mature woodlands. 70 isolates of entomopathogenic fungi were obtained from 400 samples of soil. Hyphomycete fungi (15.8% occurrence) were isolated from significantly more samples of soil than entomophthoralean fungi (1.8% occurrence, P < 0.01). The two more common species of fungi were Beauveria bassiana (6.0% occurrence) and Paecilomyces farinosus (5.0% occurrence). Entomopathogenic fungi were isolated from significantly more samples of soil from the woodland and hedgerow habitats than from the arable field (P < 0.01). There was also a significant difference in the occurrence of entomopathogenic fungi between the four woodlands (P < 0.05). 17 isolates of entomopathogenic nematodes (4.3% occurrence) were identified by RFLP analysis, including two species of Steinernema: S. feltiae and an unnamed species designated Steinernema sp. Cl. Overall, nematodes were isolated from significantly more samples of soil from hedgerow and woodland than from the arable field (P < 0.01). (C) 1997 Elsevier Science B.V.