Bioinsecticide-predator interactions: azadirachtin behavioral and reproductive impairment of the coconut mite predator Neoseiulus baraki

PLoS One. 2015 Feb 13;10(2):e0118343. doi: 10.1371/journal.pone.0118343. eCollection 2015.

Abstract

Synthetic pesticide use has been the dominant form of pest control since the 1940s. However, biopesticides are emerging as sustainable pest control alternatives, with prevailing use in organic agricultural production systems. Foremost among botanical biopesticides is the limonoid azadirachtin, whose perceived environmental safety has come under debate and scrutiny in recent years. Coconut production, particularly organic coconut production, is one of the agricultural systems in which azadirachtin is used as a primary method of pest control for the management of the invasive coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae). The management of this mite species also greatly benefits from predation by Neoseiulus baraki (Athias-Henriot) (Acari: Phytoseiidae). Here, we assessed the potential behavioral impacts of azadirachtin on the coconut mite predator, N. baraki. We explored the effects of this biopesticide on overall predator activity, female searching time, and mating behavior and fecundity. Azadirachtin impairs the overall activity of the predator, reducing it to nearly half; however, female searching was not affected. In contrast, mating behavior was compromised by azadirachtin exposure particularly when male predators were exposed to the biopesticide. Consequently, predator fecundity was also compromised by azadirachtin, furthering doubts about its environmental safety and selectivity towards biological control agents.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Behavior, Animal / drug effects
  • Brazil
  • Cocos / parasitology
  • Female
  • Insecticides / pharmacology*
  • Limonins / pharmacology
  • Male
  • Mites / drug effects
  • Mites / physiology
  • Pest Control, Biological*
  • Predatory Behavior / drug effects*
  • Reproduction / drug effects

Substances

  • Insecticides
  • Limonins
  • azadirachtin

Grants and funding

Financial support was provided by the following Brazilian agencies: Pernambuco State Foundation for Research Aid (FACEPE), CAPES Foundation (Brazilian Ministry of Education), and the National Council of Scientific and Technological Development (CNPq). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.