New Species and Expanded Geographic Ranges of Gut Fungi and Their Symbiotic Relationship with Insect Hosts

Trichomycetes from suitable immature aquatic lower dipteran, mayfly and stonefly hosts (Baetidae, Capniidae, Chironomidae, Nemouridae, and Simuliidae) were collected and identified biweekly over a twelve month period, from an ephemeral system, Cottonwood Creek, in Boise, Idaho. The abundances of eight species of obligate endosymbionts from the genera Genistelloides, Harpella, Lancisporomyces, Paramoebidium, Smittium, and Zygopolaris were evaluated with host abundance for potential correlative relationships. The abundances of all of the examined species of gut fungi, except Smittium elongatum and S. megazygosporum, were positively correlated with the abundances of the hosts. The two species with non-significant relationships with their hosts\u27 abundance were then tested for correlations with water temperature and column depth. Only S. megazygosporum had a significant correlation with either variable, being negatively correlated with water depth. Some of the observations relate to the seasonality of the hosts. We discuss our observations of the patterns in relation to our current understanding of the ecology and biology of these endosymbionts, emphasizing the significance of and encouraging other longer-term studies and investigations of ephemeral and stressed aquatic systems