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Sex pheromone traps were used to monitor the seasonal periodicity of the fall armyworm, Spodoptera frugiperda (J. E. Smith), moth over a 2-year period at eight locations from French Guiana northward to Canada. Results indicated a seasonal progression of movement by fall armyworm from the southern most locations in the United States into Canada. Although the fall armyworm survives throughout the year in the Caribbean Basin, analysis of moth capture and meteorological data for the region provided no direct evidence that this reservoir of continuous populations contributed significantly to the influx of this pest into the temperate regions of North America where it normally does not survive the winter. Weather disturbances along the Atlantic seaboard of the northeastern U.S. and Canada in October 1984 and an associated precipitous decline in moth captures in pheromone traps supports a previous hypothesis of a return (southward) migration by fall armyworm.

The spatial distributions of symptomatic tomato and pepper plants infected with tomato spotted wilt virus (TSWV) were mapped over time in field studies in 1990 to 1992. Disease gradients occurred in some tomato transplant beds and pepper fields but were not observed in tomatoes grown to maturity. In 1990 and 1991, an increasing gradient emanated from the eastern edge of tomato transplant beds and led to adjacent tobacco plots containing TSWV-infected plants. In addition, gradients within each block emanating from the edge adjacent to fallow alleys were observed within the primary disease gradient in 1990. A gradient also occurred both down the row and across cultivars in a commercial pepper field in 1990. The gradient failed to flatten over time, a possible indication of lack of secondary disease spread. Tests for aggregation supported the contention that there was limited secondary spread within pepper fields and tomato plots and that most infections arose from primary transmission. Clipped plants from tomato transplant beds had no higher incidence of TSWV in grow-out tests than did nonclipped plants. Reduced yields were significantly correlated with time of first symptom expression in tomato, with plants that were symptomatic earlier in the season yielding less fruit per plant by weight.

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