A number of control strategies are employed in the boll weevil eradication program; one of these strategies involves areawide applications of ULV malathion to cotton fields. Studies were conducted to determine if efficacy of applications of ULV malathion is altered from application on dew-laden cotton canopies as compared to application on dry canopies. It was found from both chemical residue analyses and weevil bioassays that malathion residues and weevil mortalities were not adversely affected when applications were made on dew-laden wet canopies when compared to applications on dry canopies.