Diversity of the insect pathogenic fungi in the genus Metarhizium in New Zealand

Invertebrate-pathogenic fungi in the genus Metarhizium are commonly found throughout the world on a wide range of different arthropod hosts. Some strains have been developed as biopesticides and many others have shown potential for controlling important insect pests. Given the current interest in using these fungi, precise identification at species level is crucial, both for understanding their diversity and ecology and for regulatory approval and monitoring of new biopesticides. Metarhizium has undergone extensive systematic revision over the last decade, resulting in a large number of name changes and new species. This has created regulatory issues in New Zealand and importation of biocontrol strains has become difficult due to a lack of knowledge of which Metarhizium species are present in the country. This study identified Metarhizium isolates held in culture collections in New Zealand following analysis of sequence data from the ef-1α, β-tubulin, rpb1, and ITS regions. Our results show that M. anisopliae, M. brunneum, M. frigidum, M. novozealandicum, M. pemphigi, M. rileyi and M. robertsii occur naturally in New Zealand on native and introduced insect hosts. Exotic Metarhizium species from several countries, stored in New Zealand collections, include M. acridum, M. lepidiotae, M. majus and M. pingshaense.