Monitoring of Heliothis virescens (F.) adult populations for pyrethroid resistance using a via bioassay was conducted during the 1988 growing season in Mississippi. Resistance levels in 1988 followed the same trend as in 1987 for all locations in Mississippi. The highest levels of resistance occurred in the western delta (Washington County) while the lowest levels were found in the eastern hills (Monroe County). Resistance levels increased as the season progressed at all locations. The frequency of resistance in the population in Washington County in the early spring of 1988 was much lower than that observed in the late fall of 1987. H. zea (Boddie) adult Populations showed no increase pyrethroid resistance based on the monitoring technique.