INFLUENCE OF PLANTING DATE ON THE SEASONAL ABUNDANCE OF TOBACCO BUDWORMS (LEPIDOPTERA, NOCTUIDAE) AND TOBACCO APHIDS (HOMOPTERA, APHIDIDAE)ON GEORGIA FLUE-CURED TOBACCO

The influence of planting date of flue-cured tobacco, Nicotiana tabacu m L., on the seasonal abundance of tobacco budworms, Heliothis viresce ns (F.), and tobacco aphids, Myzus nicotianae Blackman, was examined i n field plots in Georgia during 1987-89. Tobacco aphid population dens ities (aphids per plant) were influenced by yearly effects; however, t obacco budworm populations (budworms per 10 plants) were similar among the three years. A planting date (PD) effect (late March, mid-April, late April) was observed for tobacco aphids only in 1989, when higher population densities occurred in the late-planted tobacco. Planting da te influenced tobacco budworm population densities in two of the three years. Significant differences in tobacco aphid populations were dete cted between PD's in all three years for the weekly samples in June an d July, the period when seasonal aphid densities were the highest. Pop ulation peaks were higher in the mid-and late planting dates, except i n 1987 when high aphid densities (3000 per plant) occurred only during the early planting date. Weekly differences in tobacco budworm popula tions also were detected among planting dates on many sampling dates t hroughout the season in all three years. Tobacco budworms occurred ear liest in the early-planted tobacco, but peak densities were highest in the late-planted tobacco. Both tobacco budworm and tobacco aphid popu lations declined after the plants were topped (terminal floral branch removed) and a fatty alcohol sucker control was applied.