When is it biological control? A framework of definitions, mechanisms, and classifications

Johan A Stenberg,Mattias Jonsson,Hanna Friberg,Mukesh Dubey,Paul A Egan,Guillermo Rehermann,Paul G Becher,Dan F Jensen,Ingvar Sundh,Christer Björkman,Sammar Khalil,Ramesh R Vetukuri,Velemir Ninkovic,Magnus Karlsson,José F Gil,Maria Viketoft

doi:10.1007/s10340-021-01354-7

Johan A Stenberg, Mattias Jonsson + Show 14 more

Open Access

https://doi.org/10.1007/s10340-021-01354-7

Copy DOI

Abstract

Biological control, or biocontrol, is the exploitation of living agents (incl. viruses) to combat pestilential organisms (incl. pathogens, pests, and weeds) for diverse purposes to provide human benefits. Thus, during the last century the practices and concepts involved have evolved in separate streams associated with distinct scientific and taxonomic disciplines. In parallel developments, there have been increasing references to biological control in industrial contexts and legislation, resulting in conceptual and terminological disintegration. The aim of this paper is to provide a global conceptual and terminological platform that facilitates future development of the field. We review use of previously suggested terms in key fields (e.g., phytopathology, entomology, and weed science), eliminate redundant terminology, identify three principles that should underpin the concept, and then present a new framework for biological control, rooted in seminal publications. The three principles establish that (1) only living agents can mediate biological control, (2) biological control always targets a pest, directly or indirectly, and (3) all biocontrol methods can be classified in four main categories depending on whether resident agents are utilized, with or without targeted human intervention (conservation biological control and natural biological control, respectively) or agents are added for permanent or temporary establishment (classical biological control and augmentative biological control, respectively). Correct identification of what is, and is not, biological control can help efforts to understand and optimize biological pest control for human and environmental benefits. The new conceptual framework may contribute to more uniform and appropriate regulatory approaches to biological control, and more efficient authorization and application of biocontrol products.

Highlights

The term biological control has been used for more than a century (Smith 1919), and it has been applied in practice to almost all types of pests
We argue that suppressiveness that occurs spontaneously in the absence of targeted cultural practices, commonly referred to as natural or native soil suppressiveness (Siegel-Hertz et al 2018), is an example of natural biological control
We argue that classical biological control should be kept as a separate term to be used irrespectively of whether the targeted pest is exotic or native and they have co-evolved or not (sometimes referred to as neoclassical and new association biological control, respectively (Eilenberg et al 2001))

Summary

Introduction

The term biological control (or biocontrol) has been used for more than a century (Smith 1919), and it has been applied in practice to almost all types of pests. The demand for biocontrol solutions has rapidly grown in recent years in parallel with global endorsement of integrated pest management (IPM) as the future paradigm for crop protection (Stenberg 2017). In the text and conceptual framework presented here, we treat all pestilential living things, including pathogens and weeds, as pests. This is consistent with etymological roots of the words pest (Latin, pestis: pestilence, plague, curse, destruction; online-latin-dictionary.com) and pathogen (portmanteau of the Greek words, pathos and gen: producer of suffering or disease; dictionary.com)

Objectives

Conclusion