Seasonal Dispersal Patterns of Frankliniella fusca (Thysanoptera: Thripidae) and Tomato Spotted Wilt Virus Occurrence in Central and Eastern North Carolina

The seasonal abundance and temporal pattern of Frankliniella fusca Hinds dispersal were monitored from 1996 to 2000 at 12 locations in central and eastern North Carolina. The predominant vector species of tomato spotted wilt virus (TSWV) captured across all locations was F. fusca (98%). The temporal patterns of F. fusca dispersal observed during spring seasons varied among locations in all years except 2000. Regression analysis estimated that times of first flight in the spring seasons varied among locations, whereas flight duration intervals were similar. Temporal patterns of F. fusca captured varied significantly between aerial traps placed 0.1 and 1.0 m above the soil surface. Fewer total thrips were captured at 0.1 m, although thrips dispersal occurred earlier and over a greater time interval compared with 1.0-m traps. Temporal patterns of TSWV occurrence differed among locations in the spring seasons of 1999 and 2000, whereas patterns of virus occurrence were similar during the fall seasons. Patterns of F. fusca dispersal and subsequent TSWV occurrence were synchronous at locations in 1999 and 2000 where the greatest number of TSWV lesions was recorded. Knowledge of the temporal patterns of F. fusca dispersal and TSWV occurrence may be a useful indicator for describing the time when susceptible crops are at highest risk of TSWV infection.