Sugar Esters from Nicotiana Species as Potential Insecticides Against the Sweetpotato Whitefly (Homoptera: Aleyrodidae)

Eight Nicotiana species and three species accessions were grown and their sugar esters were isolated. Nicotiana trigonophylla, N. palmeri, and N. glutinosa gave the highest sugar ester yields. Sugar ester isolates were bioassayed at concentrations from 1.0 to 0.05 mg/ml against nymphs of Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae). The highest mortalities were observed with isolates from N. gossei and N. langsdorffii. As the sugar ester isolate from N. gossei contained both sucrose esters and glucose esters, these were bioassayed separately and both caused high mortality. The isolates of three N. glutinosa accessions varied in sucrose ester and labdane terpenoid content; labdane fractions were less toxic than sucrose ester fractions. Nicotiana glutinosa 24, N. langsdorffii, and N. trigonophylla, in addition to N. gossei, showed good potential as sources of biorational insecticide against whitefly.