Influence of Planting Date on the Seasonal Abundance of Tobacco Budworms (Lepidoptera: Noctuidae) and Tobacco Aphids (Homoptera: Aphididae) on Georgia Flue-Cured Tobacco

Abstract

The influence of planting date of flue-cured tobacco, Nicotiana tabacum L., on the seasonal abundance of tobacco budworms, Heliothis virescens (F.), and tobacco aphids, Myzus nicotianae Blackman, was examined in field plots in Georgia during 1987–89. Tobacco aphid population densities (aphids per plant) were influenced by yearly effects; however, tobacco 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 date influenced tobacco budworm population densities in two of the three years. Significant differences in tobacco aphid populations were detected between PD's in all three years for the weekly samples in June and July, the period when seasonal aphid densities were the highest. Population peaks were higher in the mid-and late planting dates, except in 1987 when high aphid densities (3000 per plant) occurred only during the early planting date. Weekly differences in tobacco budworm populations also were detected among planting dates on many sampling dates throughout the season in all three years. Tobacco budworms occurred earliest in the early-planted tobacco, but peak densities were highest in the late-planted tobacco. Both tobacco budworm and tobacco aphid populations declined after the plants were topped (terminal floral branch removed) and a fatty alcohol sucker control was applied.