SAMPLING AND OCCURRENCE OF ENTOMOPATHOGENIC FUNGI AND NEMATODES IN UKSOILS

The occurrence of entomopathogenic fungi and nematodes was measured in samples of soil collected from cultivated and uncultivated habitats i n Warwickshire, UK. Fungi and nematodes were isolated from the samples of soil by ''baiting'' with larvae of the wax moth, Galleria mellonel la (Lepidoptera: Pyralidae). Following two pilot experiments, a main s tudy was done using soil collected from an arable field, a network of hawthorn hedges and four mature woodlands. 70 isolates of entomopathog enic fungi were obtained from 400 samples of soil. Hyphomycete fungi ( 15.8% occurrence) were isolated from significantly more samples of soi l than entomophthoralean fungi (1.8% occurrence, P < 0.01). The two mo re common species of fungi were Beauveria bassiana (6.0% occurrence) a nd Paecilomyces farinosus (5.0% occurrence). Entomopathogenic fungi we re 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 f ungi between the four woodlands (P < 0.05). 17 isolates of entomopatho genic nematodes (4.3% occurrence) were identified by RFLP analysis, in cluding two species of Steinernema: S. feltiae and an unnamed species designated Steinernema sp. Cl. Overall, nematodes were isolated from s ignificantly more samples of soil from hedgerow and woodland than from the arable field (P < 0.01). (C) 1997 Elsevier Science B.V.