Transmission Efficiency of the Strain PVYNTN by Commonly Captured Aphids in Tunisian Potato Fields

In the context of Potato virus Y epidemiological study, fourteen aphid species were selected to investigate their relative transmission efficiency in laboratory using tobacco plant tests Nicotiana tabacum var. Xanthi. These aphid species were the ones most often trapped in Yellow Water Traps (YWTs). Transmission efficiency was evaluated in both winged and wingless individuals in cages under controlled conditions. The transmission efficiencies obtained varied from 3 to 95%. Besides Myzus persicae (Sulzer), a highly efficient vector, 13 other aphid species were screened for their capability of transmitting PVYNTN. Three aphid species, Aphis spiraecola Patch, A. gossypii Glover and Brachycaudus helichrysi (Kaltenbach), appeared to propagate PVY greatly, with transmission efficiencies of 73, 71 and 68%, respectively. Even though Aphis fabae Scopoli was less efficient, with only a moderate efficiency of 43%, it is also suspected of being implicated in PVY dissemination. In 60% of the cases, results obtained from wingless and winged forms were very close. Consequently, five aphid species seem to represent a real risk for the spread of viruses given their abundance in traps.