Biodiversity and seasonality of gut fungi associated with arthropods in Cottonwood Creek, Boise, Idaho

The phylum Zygomycota is a diverse group of nonzoosporic fungi that traditionally has consisted of two classes, Zygomycetes and Trichomycetes. Trichomycetes, commonly called “gut fungi”, are microscopic hair-like fungi that have evolved a unique endosymbiotic relationship in the digestive tracts of various arthropods. Gut fungi are heterotrophic, obtaining nutrients by absorptive means within the host gut. Many species of these fungi are commonly associated as obligate symbionts of immature stages (larvae and nymphs) of insects, but others are harbored by adult arthropods as well. To date, there are no reports of gut fungi in Idaho, and our knowledge of the biodiversity of this group in the Pacific Northwest is limited, in general. Preliminary surveys are underway to assess the biodiversity and seasonality of Harpellales and other Trichomycetes in an ephemeral stream system, Cottonwood Creek Low, located in an urban setting near Military Reserve in Boise, Idaho. This long term study is a bit unusual in that temporal change in species presence, abundance and prevalence of gut fungi will be documented across multiple seasons. Additionally, Cottonwood Creek Low is an ephemeral system, presenting habitats potentially undersurveyed compared to permanent pristine stream systems that are more commonly sampled for gut fungi during routine surveys. We report on the species of gut fungi recorded with their prevalence after the first two seasons of collecting.