Leptographium piriforme sp. nov., from a taxonomically diverse collection of arthropods collected in an aspen-dominated forest in western Canada

Abstract

During a survey of fungi associated with arthropods collected in a southern boreal mixed-wood forest in Alberta we obtained 29 isolates of a unique species of Leptographium. This species displayed a distinct combination of characteristics, including curved conidia on short-stipitate conidiophores, a secondary micronematous conidial state, stalked pear-shaped cells and an optimal growth rate at 35 C, and is described as Leptographium piriforme sp. nov. The isolates were most similar morphologically to L. crassivaginatum, but ITS sequence comparisons indicate that our isolates cannot be assigned to this or any other sequenced species in the genus. Initial observations on the pear-shaped cells in feeding experiments with Sancassania berlesei show that these structures may act as a nutritional incentive for visiting arthropods. Most arthropods carrying this new species were caught in traps baited with dung which, in light of its optimum growth temperature, suggests a coprophilous phase in the life cycle of this species. Additional isolates from woody species typical of the survey area might clarify whether Leptographium piriforme in its forest habitat occurs as a plant pathogen or saprobe.

• Bromatia
• Coprophilous
• Leptographium
• ITS
• Morphology
• Ophiostomatales

This work was made possible by a Challenge Grant in Biodiversity to MDG and by a Natural Sciences and Engineering Research Council of Canada Discovery Grant to RSC. Technical assistance with SEM images was provided by Dr Ming Chen. The authors thank Marcie Plishka and Ben Wilson for assistance with field work. We also thank Michael Hertwig-Jaksch for providing the Latin translation.