Analyses of the stomach deposit that develops in Myzus persicae feeding on sugar beet

The white deposit, commonly found in the stomach of aphids that feed on sugar beet (Beta vulgaris ssp. saccharifera L), turns a dark colour just prior to the death of the aphid, suggesting that chemical changes causing the deposit to darken may be associated with the death of the aphid. Chemical analyses of the white and dark stomach deposits by HPLC after hydrolysis, elemental analysis and FAB-MS, showed that the dark deposit is formed after the loss of hydrogen and oxygen from the organic white deposit, and that it appears to be a complex that is not dominated by any given compound. These results contrast with those of:previous studies, in which the white precipitate was described as a polysaccharide or a mucopolysaccharide.