RELATIVE ATTRACTIVENESS OF TOBACCO ETCH VIRUS-INFECTED AND HEALTHY FLUE-CURED TOBACCO PLANTS TO APHIDS (HOMOPTERA, APHIDIDAE)

The relative attractiveness of tobacco etch virus (TEV) infected versu s healthy flue-cured tobacco plants to alighting aphids under field co nditions was evaluated in 1985 and 1986. In 1987, the effect of plant age and time of inoculation on aphid alighting was also evaluated. Man y more aphids (4 species, 2 genera) were attracted to TEV-infected pla nts than to healthy plants in the Ist half of the growing season. Howe ver, no significant trends were detected for the 2nd half of the growi ng season. The relative attractiveness of TEV-infected plants compared with healthy plants was greater in 1985 than 1986 or 1987. The tobacc o cultivar used in 1985, 'NC 2326', showed much more pronounced TEV-in duced chlorotic mottling of young leaves, compared with 'Coker 176', w hich was used in 1986 and 1987 and exhibited more subtle symptoms of T EV infection. Younger plants were more attractive to alighting aphids early in the growing season.