Insect pathogenic fungi play an important role in controlling insect populations and are therefore considered as potential biocontrol agents of insect pests. Although there is a large body of research which provides insights into the pathogenicity of insect pathogenic fungi, there has been less emphasis placed on the ecology of these organisms. Recent studies have discovered that certain isolates of entomopathogenic fungi species are rhizosphere competent and even endophytic, while still maintaining the ability to infect insects in laboratory bioassays. Among isolates of Beauveria bassiana, pathogenicity may be demonstrated in bioassays but these same isolates may not be observed to infect insects in the field for reasons that are unclear. It is therefore necessary to understand the ecology of these candidates, prior to selecting them as biocontrol agents. The purpose of this research was to ascertain whether certain isolates of B. bassiana and B. caledonica colonise the rhizosphere of pine (Pinus radiata) and other plant species.