Interactions among predators and phytophagous mites on apple; possible impact on biocontrol of Panonychus ulmi by Typhlodromus pyri in orchards

Abstract

Laboratory experiments were conducted to determine the potential impact of the phytoseiid Euseius finlandicus, the mirid Blepharidopterus angulatus and the anthocorid Orius majusculus on the Typhlodromus pyri/Panonychus ulmi predator/prey relationship on apple. Euseius finlandicus consumed more immature spider mites than did T. pyri. When both phytoseiids were present and spider mite prey was abundant, there was no evidence of a negative interaction between the predators. In experiments where each predatory mite was confined with large numbers of the other predator, interspecific predation was exhibited by adults of each species on immatures of the other, but more so by E. finlandicus. In the predatory insect/phytoseiid experiments, when confined with spider mites and large numbers of T. pyri, both B. angulatus and O. majusculus consumed some T. pyri, but spider mites were the preferred prey. In experiments with B. angulatus, O. majusculus and T. pyri feeding on P. ulmi, there was no evidence of negative interactions between the predatory insects and T. pyri.

Keywords:

• Panonychus ulmi
• Typhlodromus pyri
• Euseius finlandicus
• Blepharidopterus angulatus
• Orius majusculus
• interactions
• biocontrol
• apple

Acknowledgements

This work was funded by the UK Department of Environment, Food and Rural Affairs (Defra). We thank Mike Easterbrook for technical assistance and John Fenlon for statistical analysis.