An Electronic Measuring System to Record Aphid Salivation and Ingestion1

Abstract

A detailed description of the system used to record salivation and ingestion activities of the pea aphid, Acyrthosiphon pisum (Harris), is presented. Recent modifications to the system also have been included. Selected electronic principles are discussed and are related to applicable parts of the system. Results of some voltage and resistance measurements are given, and these are used to calculate the current through, the voltage across, and the resistance of pea aphids when probing broadbean, Vicia faba L. Twelve resistance measurements were made on 3 leaves at 4 distances from the point where voltage was applied to the leaves. The voltage measurements were made during maximum conductance of current through the salivary canal of the aphids. Twenty-five aphids were used for the voltage measurements. Three broadbean leaves were used as the probed substrates. With 0.5 volts a-c applied to each leaf, the current through the aphid was found to be 3.72×10⁻⁶ amperes. The voltage across the aphid at this time was calculated to be 0.495 volts. The resistance of the aphid was 99 megohms during the time of maximum conductance.