Host plant preferences and detection of host plant volatiles of the migrating psyllid species Cacopsylla pruni, the vector of European Stone Fruit Yellows

Abstract

Plant-emitted volatile organic compounds play an important role in plant–insect interactions. Thanks to plant-emitted volatiles, herbivores are able to find suitable hosts. Recognition and location of host plants are a key challenge for successful survival and reproduction of migrating insects, such as the plum psyllid Cacopsylla pruni. This psyllid migrates between Prunus spp. for reproduction and conifers for overwintering. C. pruni also is the only known vector of ‘Candidatus Phytoplasma prunorum’, a plant pathogen causing the European Stone Fruit Yellows, a severe plant disease. The preference of C. pruni for different Prunus species was monitored in the field. The sampling revealed a high abundance of C. pruni on Prunus spinosa, the natural host, as well as on different Prunus rootstock suckers. To investigate the influence of volatile profiles from different plants on the host preferences of C. pruni, the volatiles of two reproduction hosts and one overwintering host were sampled and analyzed by gas chromatography and mass spectrometry. The volatile compositions were compared, and important components that lead to the differentiation between plant species and growth stages were identified. Antennal responses of C. pruni females were elicited by eleven plant species and growth stage-specific volatiles, detected by electroantennography. The role of host plant volatiles on the migration behavior and the use of synthetic components in alternative control strategies are discussed.