Pattern of chrysanthemum yellows phytoplasma (CYP) multiplication in three leafhopper vector species (Cicadellidae Deltocephalinae)

The titre of chrysanthemum yellows phytoplasma (CYP, “Candidatus Phytoplasma asteris”) in the three vector species Euscelis incisus, Euscelidius variegatus and Macrosteles quadripunctulatus has been measured following controlled acquisition from infected source plants. Phytoplasma DNA was quantified in relation to insect DNA (genome units, GU, of phytoplasma DNA/ng of insect DNA) using a quantitative real time PCR procedure. The results provided evidence of phytoplasma multiplication in the three species although CYP multiplication over time in M. quadripunctulatus was faster than in E. incisus and E. variegatus. CYP titre was also highest in M. quadripunctulatus. This latter species showed the shortest latent period and the highest transmission efficiency.