Lethal effects of the wild potato Solanum bulbocastanum on the planthopper Pentastiridius leporinus, a vector of bacterial pathogens in potato

The planthopper Pentastiridius leporinus [Hemiptera: Cixiidae] is a vector of the two plant pathogenic bacteria Candidatus Arsenophonus phytopathogenicus and Candidatus Phytoplasma solani in potato. An infection leads to symptoms such as rubbery and non-processable tubers and consequently to substantial decreases in yield and tuber quality as well as to abandonment of seed potato production in affected areas. Up to date, resistant potato varieties are not yet known, and the tool box of integrated pest management to prevent the spread of P. leporinus as causal vector is quite limited. Mortality experiments designed as no-choice trials on potato cultivar Gala (Solanum tuberosum) and on its wild relative S. bulbocastanum revealed significant effects of the latter on the survival rate of the vector. LC/MS analysis of the insects and their intestines showed that acyl solamines were retrieved only in individuals from the S. bulbocastanum plants. Furthermore, choice-tests were carried out to study the vector behavior. A preference towards S. bulbocastanum vs. S. tuberosum Gala was observed despite its lethal effects. Volatile organic compounds of the two different species were collected and analyzed by GC/MS. The two profiles differed in 39 of 80 compounds. The wild potato species S. bulbocastanum and its compounds are discussed as potential starting points for further research on sustainable management of P. leporinus. Key MessageO_LIWe tested a wild potato against a planthopper which vectors pathogenic bacteria to potato C_LIO_LIWild potato led to higher mortality of the planthopper but was preferred against cultivated potato C_LIO_LIUptake assays suggest that the phloem sucking planthopper is taking up xylem sap as well C_LIO_LIAcyl solamines were only found in guts from planthoppers sucking on the wild potato C_LIO_LIOur results present a starting point for new approaches for sustainable vector control C_LI