Building up knowledge about Macropsis species (Hemiptera: Cicadellidae) associated to blackberry plants in Portugal

Abstract: An outbreak of the Rubus stunt disease occurred in blackberry plants, in the SouthWest Portugal, in the last decade. The subsequent survey looking up for the vector responsible for its dissemination, revealed the presence of Macropsis scotti Edwards (Hemiptera: Cicadellidae) in blackberry plants both in greenhouses and in open field. The transmission of the phytoplasma responsible for the disease was attributed to this leafhopper. Literature is scarce on the bioecology of M. scotti, which limits our capacity to manage its occurrence and avoid the spread of the disease. In 2023, the entomological data collected in the region were published: variability of coloration in this species was evidenced, as well as its presence both in cultivated and in wild blackberry plants; detection dates, abundances, number of generations were calculated for three years, taking in consideration however that the sampling periods did not cover the whole year. Research was continued to clarify aspects of its population dynamics. Additionally, other Macropsis species were searched for, because Macropsis spp. are recognized vectors of the phytoplasma concerned in Rubus plants. M. scotti is monophagous to blackberry plants, but the producers in the region are concerned that the disease will spread to other Rubus crops, such as raspberry, which is economically more important there. The results of this research will contribute to the development of a management strategy for this pest.