The spatial distribution of canopy-resident and ground-resident cereal aphids (Sitobion avenae and Metopolophium dirhodum) in winter wheat

Linton Winder,John M Holland,Chris Woolley,Joe N Perry,Colin J Alexander

doi:10.1007/s11829-012-9216-1

Abstract

We investigated, within two cereal fields in Southern England, the within-canopy spatial distribution of the aphids Sitobion avenae and Metopolophium dirhodum in relation to crop yield and plant nitrogen. We extended the study to investigate the spatial distribution of aphids that fell to, or returned from, the ground in order to estimate availability of the within-canopy aphid population to ground-active predators. We revealed that crop canopy aphid spatial pattern was associated with nitrogen or yield. Differences were evident between species: S. avenae was generally negatively associated with yield or plant nitrogen, whilst M. dirhodum exhibited positive association. For both aphid species, we observed strong spatial pattern for aphids falling to the ground and conclude that this could, in part, mediate the effectiveness of ground-active predators as pest control agents.

Highlights

Aphids are common pests of cereal crops and are known to have patchy within-field distributions (Alexander et al 2005; Winder et al 2001; Winder et al 1999)
We investigated, within two cereal fields in Southern England, the within-canopy spatial distribution of the aphids Sitobion avenae and Metopolophium dirhodum in relation to crop yield and plant nitrogen
The first part of this study investigated the spatial distribution of cereal aphids infesting the crop and used yield and crop nitrogen measurements as simple indicators of crop quality

Summary

Introduction

Aphids are common pests of cereal crops and are known to have patchy within-field distributions (Alexander et al 2005; Winder et al 2001; Winder et al 1999). Such patchy distributions are important because spatial pattern is likely to mediate the amount of damage caused by aphids through direct yield loss (Mowes et al 1997), reduction in quality (Basky and Fonagy 2007) or virus transmission (Chapin et al 2001). We hypothesised that aphid spatial pattern would be associated with these host plant characteristics and measured soil moisture as it is known to influence aphid development (Ehsan-Ul-Haq and Van Emden 2003) and epigeal natural enemy spatial pattern (Holland et al 2007)

Methods

Results

Conclusion