The seasonal occurrence and relative abundance of adult Phllophaga species associated with sweet potato growing areas in Louisiana has been determined with a two year survey using blacklight traps. The optimum ratio of two amino acids (pheromone composition: blends of methyl esters of L-isolucine and L-valine) for attractiveness to adult male P. ephilida was determined to be 100% L-isolucine. A cage study was used to determine that the life cycle of this species in south Louisiana is univoltine. The relationships between pheromone trap catch of adult Phyllophaga ephilida in grower fields with subsequent white grub damage to sweet potato roots, proximity of tree lines, and harvest date, have been examined with regression and correlation analysis. These data were obtained from 19 grower fields in a two year study in which pheromone traps were monitored weekly through the growing season, and roots were dug and evaluated for white grub damage at harvest.