MacStylet, software to analyse electrical penetration graph data on the Macintosh

Abstract

The feeding behaviour of Homoptera is now largely studied using the technique of electrical recording originally developed by McLean & Kinsey (1964) and improved by Tjallingii (1978). The recorded signal, the electrical penetration graph (EPG), gives direct information on stylet movements and their location in the plant tissues, and on elementary feeding activities. In the case of aphids, the different EPG patterns were defined by Tjallingii (1988) and precisely described in terms of amplitude and frequency. The use of EPG in combination with other techniques (microscopy, stylet amputation, radioactive tracers, electromyography, virus acquisition and transmission) has allowed EPG patterns to be related to stylet penetration or other aphid activities such as cell puncture, salivation, xylem or phloem ingestion and mechanical stylet activities. Also, many relevant behavioural variables can be determined, such as the number, duration and succession of different patterns (van Helden & Tjallingii, 1993; Caillaud et al., 1995; Sauvion, 1995).