The worldwide importance of Grapevine Trunk Diseases (GTDs; e.g. esca) highly increased in the last centuries and threatens viticulture. A diversity of fungal pathogens invades the grapevines through pruning wounds and colonizes the vascular system leading to a high decrease in productivity and longevity of vineyards. Phaeomoniella chlamydospora (Pch) and diverse Phaeoacremonium-species are the main actors of the disease complex esca. The pathogens are said to be dispersed by air currents and rain splashes.
Additionally, arthropod-mediated dispersal of Pch was demonstrated in South Africa. Ants, spiders and millipedes frequently carried spores of Pch on their exoskeleton. Further, the infection of pruning wounds with Pch after being vectored by ants and millipedes was confirmed. In German vineyards, airborne spores of Pch were detected many times by means of spore-traps. In contrast, arthropod-mediated dispersal of Pch in German vineyards has not yet been documented.
The aim of the present study is to determine i) the arthropod diversity present on the vine trunk in the context of the pruning season, ii) the occurrence of esca-related pathogens on arthropods’ exoskeletons using molecular techniques (nested PCR), iii) the possibility of ants and earwigs vectoring esca-related pathogens to wounded grapevine cuttings, and iv) the chance of earwig feces as inoculum source for esca-related pathogens. Results collected in this study will give us further information about the epidemiology of important GTD-pathogens and eventually can help to develop measures reducing the spread of esca.
