Honeydew from the sweetpotato whitefly [Bemisia tabaci (Gennadius)], feeding upon upland cotton (Gossypium hirsutum L.), was analyzed by several chromatographic techniques. Approximately half of the sugars in this honeydew were found to be the unusual disaccharide trehalulose. More than 20% of these sugars were oligomers larger than disaccharides, and oligomers larger than 1,000D were detected in this mixture. Several of the sugar components in this honeydew have structures based upon , -trehalose and at least one of these unusual components has not been reported to occur elsewhere in nature. The majority of the components of this honeydew (>80%, w/v) are nonreducing, which explains why many sugar tests fail to accurately measure lint contamination. Exposure of whitefly honeydew to relatively short periods of weathering on cotton tissues seems to have little effect upon its chemical composition. However, Tempanil, a commercial preparation for the alleviation of honeydew stickiness, was found to significantly reduce soluble sugars on sweetpotato whitefly honeydew-contaminated cotton lint.