Patterns of aphid resistance in the genus Vicia

SUMMARY The performance of three aphid species, Aphis fubae, Acyrthosiphon pisum and Megoura viciae, was quantified on 22 taxonomically‐selected host plant species from the genus Vicia (vetches), using intrinsic rate of increase (rm) k standard errors. A. pisum proved to be the most successful aphid species, both in terms of highest potential population increase and widest host range; M. viciae was least successful, with most restricted host range and low rm values on all but the closest relatives of Vicia faba. A wide range of antibiotic resistance was found within the genus, and host resistance to the three aphid species was found to be broadly related to classification patterns based on taxonomy and life‐form. Analysis of the components of rm revealed that nymphal survival rates were the most significant factor limiting host colonisation, not pre‐reproductive period which is the most important factor in cultivars of V. faba. The consequences of aphid polyphagy on performance are discussed.