Studies on the quantitative uptake of 32P-labelled Trakephone by aphids

The present paper reports methodical studies concerning the quantitative uptake of active substances by Acyrthosiphon pisum (Harris) and Aphis fabae Scop. on Vicia faba L. enriched by 32P-labelled Trakephone. Aphids increasing in size were found to take up rising quantities of active substance. The uptake is the more continuous the more sessile the pests are. Feeding is delayed by the presence of Trakephone in the plant. The quantification of the active substance amounts is only practical in parts per million using the weight of the aphids. Higher concentrations of active substances in the plant will increase the uptake by the aphids. The autoradiogram qualitatively demonstrates the beginning of the uptake of active substances. It may be taken into consideration for examining the repellent properties of chemical compounds towards aphids. (author)