Orientation of specialist and generalist fungivorous ciid beetles to host and non-host odours

Most ciids (Ciidae) are strict fungivores specialized on fruit bodies of wo od-rotting fungi. The Ciidae includes both specialist and generalist specie s. Recent evidence suggests that ciids locate and discriminate their potent ial hosts based mainly on fungal odours. In this study, we investigated the field distribution of ciids in a local woodland near Bath, U.K. We also ev aluated experimentally the behavioural responses of ciids to host and non-h ost fungi in an olfactometer, and explored potential differences in putativ e aroma compounds in host fungi. Our field data showed that Octotemnus glabriculus, Cis boleti and Cis nitid us have preference for one host species. whereas C. bilamellatus has no pre ference. The experimental evidence was in accordance with the held observat ions. The specialists O. glabriculus, C. boleti and C. nitidus were specifi cally attracted to odour compounds of their preferred host fungi: Coriolus versicolor for the first two beetles and Ganoderma adspersum for the latter one. By contrast, the generalist C. bilamellatus was attracted to odours f rom C. versicolor, G. adspersum and Piptoporus betulinus. The evidence from this and other published studies suggest that ciids depen d mainly on fruit body odours for location and discrimination of their host fungi. In accordance with this, we observed differential behavioural respo nses of ciids to aroma compounds of host and non-host species.