Abstract

Public health and environmental concerns are increasing the pressure to reduce chemical pesticide usage, thereby requiring management alternatives to control pest damage to crops. Retaining semi-natural habitats within agricultural landscapes is often assumed to be one such alternative, by contributing to boost natural enemy populations and reduce pest abundance and spread. However, these potential benefits might be diluted or counteracted by intensive field management, thus limiting their effectiveness. We test these hypotheses, focusing on olive farming in southern Portugal, where we quantified the abundance of three pests, the olive fruit fly (Bactrocera oleae), olive moth (Prays oleae) and olive psyllid (Euphyllura olivina), and their parasitism and infestation rates in 17 orchards representing an intensification gradient and varying landscape cover by oak woodlands. Fly infestation was lower in more intensive orchards, there were no woodland effects, and parasitism was never detected. Psyllid infestation was also lower in more intensive orchards, but declined with woodland cover in more intensive orchards, while slightly increasing in less intensive ones. Psyllid parasitism rate could not be confidently estimated. Moth infestation declined with woodland cover in the most intensive orchards, while varying little in less intensive orchards. Moth parasitism rate declined with intensification and increased with woodland cover, particularly in less intensive orchards. Infestation by the moth was positively related to its abundance, albeit less so when parasitism rates were higher. Overall, our findings show mixed effects of oak woodlands, although retaining such habitats might still enhance biocontrol potential and reduce pressure by some pests, even under management intensification.

Keywords

Agricultural intensification; Mediterranean; Olea europaea; Biological control; Parasitoids; Structural equation models

Published in

Journal of Pest Science
2024, Volume: 97, number: 1, pages: 355-368
Publisher: SPRINGER HEIDELBERG

SLU Authors

• Vasconcelos, Sasha

  • Department of Ecology, Swedish University of Agricultural Sciences
    
  • University of Lisbon
  • University of Porto

• Jonsson, Mattias

  • Department of Ecology, Swedish University of Agricultural Sciences
    

• Lamprini Daouti, Eirini

  • Department of Ecology, Swedish University of Agricultural Sciences
    
  • Department of Crop Production Ecology, Swedish University of Agricultural Sciences
    

Associated SLU-program

SLU Plant Protection Network


UKÄ Subject classification

Ecology
Agricultural Science


Publication identifier

DOI: https://doi.org/10.1007/s10340-023-01634-4

Permanent link to this page (URI)

https://res.slu.se/id/publ/122363