ClonalRhopalosiphum padi(L.) were reared on oats,Avena sativaL., that were either healthy or infected with the PAV strain of barley yellow dwarf Iuteovirus (BYDV). Alate aphids of known posteclosion age were tethered in a wind tunnel and exposed to air speeds of 1 m/s. Flight durations, wingbeat frequencies, and the posteclosion age of maiden flight were recorded. Both viruliferous and nonviruliferousR. padithat begin their maiden flight through the posteclosion age of 40 h appear to exhibit similar tethered flight behavior, including flight duration and the earliest age that maiden flight can commence. Viruliferous aphids older than 40 h had maiden flights of shorter duration than did their younger viruliferous counterparts. Nonviruliferous aphids maintained about the same average length of flight duration for all ages in which flight occurred. The oldest postec1osion age at which an aphid began its maiden flight was 65 and 88.7 h for viruliferous and nonviruliferous aphids, respectively. Wingbeat frequencies ofR. padiwere independent of the age at which maiden flight began and were unaffected by the presence of BYDV. These findings suggest that there is a broader window of opportunity for nonviruliferousR. padito aerially move long distances than their viruliferous counterparts.