NEW CORRELATIONS BETWEEN APHID STYLET PATHS AND NONPERSISTENT VIRUS TRANSMISSION

The electrical penetration graph technique was used to study probing b ehavior of the aphid Myzus persicae (Sulzer) during the transmission o f potato virus Y (PVY) to pepper plants. Single aphids allowed a 5-min access to infected plants achieved 51.3% transmission efficiency. Aph ids acquiring the virus probed the plant more frequently but these pro bes were shorter than the ones produced by the aphids that were unable to acquire PVY. Moreover, aphids that transmitted PVY produced more i ntracellular punctures (as measured by potential drops), but their mea n duration did not differ significantly from that of the aphids unable to transmit the virus. The mean duration of none of the potential dro p subphases could be associated with PVY transmission. Two of the 18 b ehavioral variables analyzed proved critical for virus acquisition acc ording to a stepwise logistic regression model. The 1st variable was t he total number (observed during the entire 5-min register) of typical pulses recorded during subphase II3 of the potential drops (positive correlation). Subphase II3 is the last true intracellular distinct pha se of a potential drop. The 2nd variable was the time elapsed from the last potential drop to the end of the probe (negative correlation). T he implication of these results an the transmission mechanisms of nonp ersistently transmitted viruses is discussed.