Five novel Candida species in insect-associated yeast clades isolated from Neuroptera and other insects

Abstract

Ascomycete yeasts are found commonly in the guts of basidioma-feeding beetles but little is known about their occurrence in the gut of other insects. In this study we isolated 95 yeasts from the gut of adult insects in five neuropteran families (Neuroptera: Corydalidae, Chrysopidae, Ascalaphidae, Mantispidae and Hemerobiidae) and a roach (Blattodea: Blattidae). Based on DNA sequence comparisons and other taxonomic characteristics, they were identified as more than 15 species of Saccharomycetes as well as occasional Cryptococcus-like basidiomycete yeasts. Yeast species such as Lachancea fermentati, Lachancea thermotolerans and Hanseniaspora vineae were isolated repeatedly from the gut of three species of corydalids, suggesting a close association of these species and their insect hosts. Among the yeasts isolated in this study 12 were identified as five novel Candida species that occurred in three phylogenetically distinct clades. Molecular phylogenetic analyses showed that Candida chauliodes sp. nov. (NRRL Y-27909^T) and Candida corydali sp. nov. (NRRL Y-27910^T) were sister taxa in the Candida albicans/ Lodderomyces elongisporus clade. Candida dosseyi sp. nov. (NRRL Y-27950^T) and Candida blattae sp. nov. (NRRL Y-27698^T) were sister taxa in the Candida intermedia clade. Candida ascalaphidarum sp. nov. (NRRL Y-27908^T) fell on a basal branch in a clade containing Candida membranifaciens and many other insect-associated species. Descriptions of these novel yeast species are provided as well as discussion of their ecology in relation to their insect hosts.

• green lacewings
• insect-fungus associations
• insect gut yeast

We thank Michael Ferro for identification of the owlflies. We acknowledge Ms Glenda Newman, principal, North Corbin Elementary School, Walker, Louisiana, for permission to collect at the school. GenBank and the NRRL and CBS collections of fungal cultures are gratefully acknowledged. This research was supported by the National Science Foundation, Biodiversity Surveys and Inventories Program (DEB-0072741 and DEB-0417180), including REU supplements. The REU supplements and a Howard Hughes Medical Institute grant through the Undergraduate Biological Sciences Education Program to Louisiana State University provided support for NHN. We also acknowledge the use of the DNA sequencing facility supported by NSF Multi-user Equipment Grant (DBI-0400797) to Robb Brumfield, and the assistance of Nannette Crochet for sequencing.