Effects of post-acquisition fast on cucumber mosaic virus transmission by the cotton aphid, Aphis gossypii

Viruliferous cotton aphids, Aphis gossypii, were treated with post-acquisition fast in the air to study cucumber mosaic virus (CMV) retention in the aphid and consequent transmission on the melon, Cumumis melo. Transmission efficiency was negatively correlated with fasting duration. The 10-min inoculation processes of fasted and non-fasted aphids were studied with electrical penetration graph (EPG) technique to search the behavior events responsible for the reduction of transmission efficiency. The total number of potential drops and the probing time before the 1st pd were usually considered as two important behavior variables correlated with transmission efficiency; however, no significant difference was found between fasted and non-fasted aphids. Fasting treatment significantly decreased the durations of sub-phase pdⅡ-1 and pdⅡ-2. Further analysis suggested that the duration of pdⅡ-2 was probably a behavioral factor correlated with the virus transmission. The related behavioral mechanism was discussed. The 5 pd acquisition method was first used in virus acquisition research and a significantly higher transmission efficiency (78.6% vs 46.40%, P0.0001) was obtained compared to the traditional 5 min acquisition method.