Factors affecting the relative abundance of two coexisting aphid species on sugar beet
1 The two most common species of aphid colonizing sugar beet Beta vulgaris L. are Myzus persicae (Sulzer) (Hemiptera: Aphididae) and Aphis fabae Scopoli (Hemiptera: Aphididae).
2 M. persicae colonizes sugar beet earlier than A. fabae but the population of the former also declines earlier. Despite similar numbers of each species migrating at the time of colonization, M. persicae is usually less abundant on the crop than A. fabae, suggesting differences between the species in their selection of, and performance on, sugar beet.
3 The intrinsic rate of increase of both species declines as sugar beet matures, however, at any given plant age the intrinsic rate of increase of A. fabae is one and a half times greater than that of M. persicae. This results in more rapid population growth and a later decline of the population.
4 Intraspecific competition appears to result in M. persicae becoming very restless, but there is no evidence for interspecific competition between the two species on this host.
5 A population growth model which takes account of the decline in host quality of sugar beet shows that the M. persicae population peaks 30 days before that of A. fabae, and, excluding differences in emigration rate, the maximum A. fabae population is 14 times greater than the maximum M. persicae population. These results are compared to field data.
Document Type: Research Article
Affiliations: 1: Wageningen Agricultural University, Department of Theoretical Production Ecology, PO Box 430, 6700 AK Wageningen, The Netherlands 2: IACR Broom’s Barn, Higham, Bury St. Edmunds, Suffolk, IP28 6NP, U.K., 3: School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, U.K.,
Publication date: May 1, 1999