ESTIMATION OF VECTOR PROPENSITY OF POTATO-VIRUS-Y IN OPEN-FIELD PEPPER CROPS OF CENTRAL SPAIN

During 3 successive years (1991, 1992 and 1993), 49 different species of aIatae aphids were captured alive using net traps located in pepper fields in central Spain (Madrid). Aphids were trapped and transferred individually to pepper test seedlings to assess transmission of potat o virus Y (PVY). In 1991, only 1 individual aphid transmitted PVY of 5 82 aphids captured. None of the 157 aphids captured in 1993 transmitte d PW to test plants. However, the percentage of transmitters was highe r during 1992 (55/780,7%). Most aphids transmitting PVY were identifie d either as Diuraphis noxia (Mordvilko) or Aphis spp. A series of tran smission assays were conducted under controlled conditions to confirm the transmission ability of D. noxia. Results showed that D. noxia tra nsmits PVY with low efficiency under laboratory conditions. The role o f D. noxia as a vector of PVY in the central region of Spain is discus sed.