| Entomopathogenic fungi cause disease in insect hosts, and past research on these fungi has focused largely on applications of the genera Metarhizium and Beauveria as biological control agents of insects. As such, the diversity of entomopathogenic fungi outside of agroecosystems---specifically in natural, pine forest soils---is poorly explored. This study seeks to isolate and identify entomopathogenic and insect-associated fungi at the Duke research forest in North Carolina using culture-dependent sampling methods, as well as to assess differences in the abundance and distribution of these taxa using traditional (Sanger) sequencing and Illumina pyrotag sequence libraries.;Two culture-dependent approaches were used. Fungi were baited using Galleria mellonella larvae, and soil samples were diluted and placed on a selective medium containing cycloheximide, chloramphenicol, and thiabendazole. Isolates from both methods were identified using Sanger sequencing of the ITS and LSU rRNA gene regions. These isolates represented three phyla---Ascomycota, Basidiomycota and Zygomycota---and a total of 42 unique OTUs, including known entomopathogenic taxa such as Lecanicillium and Paecilomyces..;Phylogenetic analysis of the Hypocreales, Mucorales, and Mortierellales resolved several isolates at the genus level, with some showing close phylogenetic placement with taxa that included fungi associated with plant tissues. Chitinolytic enzyme assays showed a widespread ability of isolates to degrade chitin, as well as considerable variation within and between genera. Culture-based and Illumina datasets showed similar relative abundances of taxa at the order level. Many taxa were widely distributed in these soils, including genera containing known entomopathogens (e.g., Lecanicillium and Paecilomyces) and other saprophytic fungi (e.g. Mucor and Mortierella). While the combination of Illumina and culture-dependent approaches used in this study is novel, our findings generally support the findings of previous studies conducted in natural soil ecosystems. |
