Fungi in the genus Metarhizium are insect pathogens that can establish as endophytes and can benefit their host plant. In field experiments, a positive correlation between the prevalence of M. robertsii and legume cover crops, and a negative relationship with brassicaceous cover crops and with increasing proportion of cereal rye in mixtures were observed. Relatively fewer studies have reported the use of cover crops for the conservation of entomopathogens for biological control. In this study, the goal was to determine the relative ability of M. robertsii isolated from soil from a field experiment to colonize commonly grown winter cover crop species.