Electrical Penetration Graph monitored feeding behavior of cowpea aphid, Aphis craccivora Koch. (Hemiptera:Aphididae), on faba bean, Vicia faba L. (Fabaceae), cultivars

Abstract

Feeding behavior of cowpea aphid, Aphis craccivora Koch. (Hemiptera: Aphididae), was evaluated on five faba bean, Vicia faba L. (Fabaceae), cultivars, including the resistant cultivar Gazira2, by using the Electrical Penetration Graph (EPG) technique. Experiments were conducted on whole plants (WP) and detached leaves (DL). Fifteen parameters of EPG recording were selected for statistical analysis. Two-way factorial ANOVA showed that the EPG parameter values in WP and DL were significantly different, while the cultivars difference occurred mostly in the WP tissue, as indicated through one-way ANOVA Kruskal-Wallis analysis. Cowpea aphid feeding behavior on WP Gazira2 resistant cultivar had the longest duration of stylet derailment (waveform F) and total probing, but lowest in total duration of pathway (waveform C), xylem ingestion (waveform G),and number of probes. Speculatively, longest duration of waveform F, which had a relation with the mechanical disturbance during feeding, probably is one of the possible resistant factors in Gazira2 cultivar, however this remains intriguing and needs further study.