Abstract

Ecological theory hypothesizes that plant trait diversity may be as important as the presence of specific functional traits (e.g., resistance) for the herbivore and predator communities within a population. We used experimental populations of wild woodland strawberry (Fragaria vesca) to test whether the degree of plant genotypic diversity and/or the existence of specific resistance traits play a role in the host plant’s community structure specifically, the community of generalist and specialist aphids and their natural enemies. In 2019, we studied the aphid abundance and relative predator abundance in an experimental field site in Alnarp, Southern Sweden; the field consisted of plots planted with combinations of 20 different wild strawberry genotypes. These strawberry genotypes were previously identified as either susceptible to or resistant against the herbivorous beetle (Galerucella tenella). Two aphid species, Chaetosiphon fragaefolii (specialist) and the exotic Aphis gossypii (generalist) were found in the plots and of the two species A. gossypii was dominant. The abundance of the specialist aphid (C. fragaefolii) was highest in susceptible plots with high genotypic diversity, while the generalist (A. gossypii) was highest in plots with a mix of resistant and susceptible plants with high genotypic diversity. Anthocorid predators, developed significantly higher population densities in strawberry plots with high genotypic diversity. Overall, predator abundance showed a positive correlation with aphid abundance. These results show that the specific functional trait of resistance as well as plant diversity affected aphids. Knowledge about these effects can be important factors to consider when designing strawberry plantings less susceptible to aphids.

Keywords

Conservation biocontrol; Conservation biological control; Cultivar mixtures; Herbivory; Genetic diversity; Plant resistance; Resistance mixtures; Woodland strawberry

Published in

Biological Control
2022, Volume: 170, article number: 104919

SLU Authors

• Stenberg, Johan A.

  • Department of Plant Protection Biology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Ecology
Botany


Publication identifier

DOI: https://doi.org/10.1016/j.biocontrol.2022.104919

Permanent link to this page (URI)

https://res.slu.se/id/publ/121400