title: Bioluminescence in the ghost fungusOmphalotus nidiformisdoes not attract potential spore dispersing insects.
abstract: Bioluminescence has been known from fungi since ancient times, but little work has been done to establish its potential role. There is evidence that some bioluminescent fungi differentially attract potential spore-dispersing insects, and we aimed to establish if this was the case for the ghost fungus,Omphalotus nidiformis(Agaricales,Marasmiaceae), a widespread Australian temperate zone species. We examined three corroborative lines of evidence: circadian rhythmicity of bioluminescence; field-recorded insect abundance at the time of basidiome production; and attractiveness of glowing fungi to flying insects. Basidiomes glowed continuously day and night, and were present in winter (June-July) when insect abundance was low. To assess attractiveness, we deployed sticky-traps in open woodland in the absence of light pollution, in Treatment (baited with fresh bioluminescentO. nidiformis) and Control pairs, for 480 trap-hours on moonless nights. There was no statistical difference in mean insect abundance between Treatment and Control traps (mean 0.33 and 0.54 individuals per trap night, respectively). To interpret these results, we provide a brief review of competing hypotheses for fungal bioluminescence, and conclude that for some fungi, bioluminescence may be an incidental by-product of metabolism rather than conferring any selective advantage. It is possible that the role of bioluminescence differs among evolutionary lineages of fungi and/or with attributes of their growth environments that could affect spore dispersal, such as wind and insect abundance.
authors.affiliation: Department of Ecology and Environmental Sciences, School of Biological Sciences, The University of Adelaide, Adelaide SA 5005, Australia.
authors.forename: Philip
authors.initials: P
authors.lastname: Weinstein
authors.affiliation: Department of Ecology and Environmental Sciences, School of Biological Sciences, The University of Adelaide, Adelaide SA 5005, Australia.
authors.forename: Steven
authors.initials: S
authors.lastname: Delean
authors.affiliation: Department of Ecology and Environmental Sciences, School of Biological Sciences, The University of Adelaide, Adelaide SA 5005, Australia.
authors.forename: Tom
authors.initials: T
authors.lastname: Wood
authors.affiliation: Australian Centre for Evolutionary Biology and Biodiversity, and Department of Genetics and Evolution, School of Biological Sciences, The University of Adelaide, Adelaide SA 5005, Australia.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Austin
keywords: Agaricales; Kangaroo Island; fungal physiology; insect-fungal interactions; spore dispersal