*Citrus Experiment Station, Gonicoppal, Coorg, Karnataka State.
**of the I.C.A.R., Plant Virus Research Station, Poona-411 005.
Plant Virus Research Station, Agricultural College Estate, Poona
The coffee aphid or the citrus black aphid, Toxoptera aurantii (B. de F.) was collected in 1966 for the first time in Poona and has been demonstrated to act as an inefficient vector of the tristeza virus. It has been shown that the aphid is unable to imbibe and transmit severe strains of the virus. Its transmission efficiency is also low, and this is believd to be due to the absence quite often in source trees of such strains (mild strains) of the tristeza virus which the aphid is able to pick up and transmit to healthy suscepts. The aphid is considered of some consequence as a vector of tristeza in regions where it colonizes on citrus all the year round.
