Can Amplicephalus funzaensis Linnavuori 1968 (Hemiptera: Cicadellidae) transmit phytoplasmas to strawberry?

Abstract

Phytoplasmas are plant pathogenic bacteria of the class Mollicutes that lack cell walls, are restricted to the phloem of their plant hosts, are difficult to culture, and are transmitted by insect vectors. Phytoplasmas from 16SrI and 16SrVII groups have been associated with diseases in urban trees in the Bogota plateau and with potato and strawberry crops in Cundinamarca,Colombia. The objective of this work was to evaluate if the vector Amplicephalus funzaensis (Hemipera: Cicadellidae) could transmit phytoplasmas to Fragaria x ananassa under semi-controlled conditions. A transmission assay on F. x ananassa var. Monterrey was performed with A. funzaensis from a population naturally infected with phytoplasmas, whose host was Cenchrus clandestinus. Seven months after herbivory by these insects, the plants did not show symptoms associated to phytoplasmas, even though more than one third of the insects used carried phytoplasmas. In total, 120 A. funzaensis individuals were tested for the presence of phytoplasmas by molecular methods; of these, 46 (38%) were positive for phytoplasmas, showing the existence of insect populations with a high number of individuals that are a potential source of inoculum for the pathogen transmission. Additionally, for the molecular identification of A. funzaensis, a DNA barcode was generated from the cyitochrome c oxidase (COI) gene.