Exotic generalist arthropod biological control agents: need to improve environmental risk assessment to ensure safe use

David A. Andow, Barbara I.P. Barratt, Robert S. Pfannenstiel, Débora Pires Paula

Research output: Contribution to journalReview articlepeer-review


Exotic generalist arthropod biological control agents (GABCAs) have been historically marginalized in classical and augmentative biological control due to their broad diet breadth, but an increasing demand for a more sustainable pest control is encouraging their reconsideration. This special issue compiles a collection of papers revealing that risks of several exotic GABCAs were overestimated, not all generalists are riskier than specialists and their environmental risk assessment (ERA) solely based on exposure analysis is inadequate. Three papers demonstrated that generalists were not involved in predicted non-target interactions: generalist idiobiont parasitoids probably do not exhibit interference competition with each other, an oligophagous exotic egg-larval koinobiont parasitoid does not compete with a native larval koinobiont, and an invasive generalist predator does not escape from its enemies. Two innovative methods for selecting non-target species are proposed, one based on existing food web data to predict indirect non-target effects, and the other on functional traits to predict competition with native natural enemies. Also a comprehensive GABCA-ERA method is proposed that integrates adverse effect analysis to the ‘conventional’ exposure analysis. The method was scrutinized by two studies: one suggesting that it could have resulted in faster and less costly decisions on two exotic generalists in New Zealand, and the other suggesting that eight exotic GABCAs released in Argentina might potentially reduce native natural enemies. We hope this special issue will stimulate the continued advance in the biosafety research of GABCAs so their safe use does not stagnate.

Original languageEnglish (US)
StateAccepted/In press - 2020

Bibliographical note

Funding Information:
We thank the many biological control experts who contributed to the works in this Special Issue. This work was funded in part by Embrapa grant number SEG, United States Department of Agriculture National Institute of Food and Agriculture Grant Number 2019-67013-29406, and the New Zealand Better Border Biosecurity Research Collaboration.


  • Augmentative biological control
  • Biosafety
  • Classical biological control
  • Host range tests
  • Non-target risks

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