Submitted to: Silverleaf Whitefly: 1997 Supplement to the Five Year National Research and
Publication Type: Abstract Only
Publication Acceptance Date: 8/1/1997
Publication Date: N/A
Technical Abstract: Approximately 200 kg of cotton fiber contaminated with honeydew was washed, 1 kg at a time, in hot deionized water. After removing the fiber by centrifugation, finely divided activated charcoal was stirred into the extracts to adsorb the sugars. Sugars were removed from the charcoal with 95% ethanol which was removed by rotary evaporation. The remaining water was then removed by lyophilization leaving 1.5 kg of a dark brown syrup. This was fractionated using a large charcoal column eluted with 40 L washes of increasing concentrations of iso-propanol. The sugars eluted with 6% propanol were collected and further separated using a large heated BioGel P-2 column eluted with deionized water. From analysis of acid digestion products of the 6% propanol fractions of various honeydews by HPLC it was determined that over 90% of the monosaccharides which make up the largest sugars in both A. gossyppi and B. argentifolii honeydew are glucose, the remainder being fructose. Some of the sugars in this honeydew are created by adding glucose units to trehalose, other sugars are created by adding glucose to sucrose. The discovery of maltosucrose is unexpected since erlose, a maltosucrose precursor in scale insect honeydew, is not present in this excretia.