Aphis craccivora and Myzus persicae were used in peanut mottle virus (PMV) transmission studies. Aphids starved 4-6 h in glass dishes were allowed to probe once on an infected leaf, and then transferred singly to healthy peanut seedlings. Both aphids transmitted 4 of the 5 known strains of PMV in a stylet-borne manner. Efficiency of transmission was similar (21-54%) for 2 mild mottle strains and the severe mosaic strain; it was significantly reduced (9-18%) for the chlorotic line pattern strain, and the necrosis strain was not transmitted by the aphids. Transmission rates were about 2 1/2 times as great for M. persicae as for A. craccivora. Also, M. persicae remained infective after acquisition for 12 h as compared to 2 h for A. craccivora. The acquisition host was usually peanut, but the transmission results were not altered when Pisum sativum, a host with a higher concentration of all strains of MV, was used. After an acquisition probe on peanut, a single probe by A. craccivora on non-PMV hosts (pepper and cotton) reduced the transmission to peanut by 50-69%. Feeding on nonhosts did not affect PMV transmission by M. persicae.