Biological Control in Plant Protection
A Color Handbook
Neil Helyer
Fargro Ltd, West Sussex, UK
Nigel D. Cattlin
Holt Studios International Ltd
Kevin C. Brown
Ecological Consultant, Plymouth, UK
Since the first edition of this book there have been dramatic increases in the commercial use of integrated crop/pest management (ICM/ IPM) methods for pest and disease control on a wide range of crops throughout the world. This has resulted in an enormous demand for mass-reared biological control agents, and the knowledge and technology to do this has improved with the demand. Some producers concentrate on a narrow range of organisms reared under highly specific conditions. Others offer a broader range. The development of ICM/IPM compatible pesticides that frequently control specific pests while having minimal side effects on beneficials allows a greater range of biological control agents to be used over a longer period and with greater success. The majority of protected crops (edible and ornamental) are now produced using these methods to control their major pests and diseases. Biological agents for the control of diseases are being used more frequently, particularly on highvalue edible crops like strawberry. Similarly, broad-spectrum pesticides are being used less extensively on field and orchard crops; consequently, growers and advisors are now finding a greater frequency and range of naturally occurring beneficials.
All these factors come together under the ICM/IPM banner as a more environmentally friendly and sustainable method for long-term pest and disease control. The majority of massreared beneficials can be used by amateur growers and are usually available by mail order for direct delivery and use in the garden, conservatory, or greenhouse. The reduction of pesticide applications in the home garden allows more natural enemies of common pests to establish. This book should help both amateur and professional growers identify many of these organisms.
Biocontrol is about the control of plants (weeds), animals (insect and mite pests but could include slugs and nematodes pests), or diseases by using another living organism, be it herbivore, predator, parasitoid, parasite, or microorganism. Unlike pesticides, biocontrol seldom kills all of the target species but aims to manage them to a level that is below the economic damage threshold.
Classical biocontrol is where a beneficial organism is released on a one-off basis— usually to control a new pest that has been introduced from elsewhere, thus reestablishing it with its former natural enemies. Frequent or inundative release of biological control agents is used in glasshouses or annual
crops where the beneficial may reproduce over a period of time but dies out at the end of the year. In some cases, particularly when microorganisms are used, they are treated like a pesticide with little residual action or subsequent reproduction. Conservation biocontrol aims to change our modern agricultural practices of a single monoculture crop grown in bare soil to one of supporting native beneficial insects by using additional plants to provide shelter and alternative sources of food.
A prerequisite for classical and inundative biocontrol is that the beneficial organism has to be available commercially or financed through some government-sponsored national release scheme. It must also be specific against the pest to be controlled. This book covers many commercially produced beneficials; because of legislation within each country, certain beneficials may or may not be permitted for use.
Biopesticides is a term frequently used when a living organism is applied in similar ways to chemical or conventional pesticides. Several pathogens (disease-causing organisms) are now available to control and help prevent pest outbreaks on a range of crops. These can include bacteria, fungi, and viruses. The majority occur naturally, but when they are used as a pesticide, similar registration conditions to chemical pesticides apply. This has been seen as restriction to their development. However, since over 60% of the active ingredients of pesticides have been withdrawn, the new biological controls are now regarded as a safer and a more sustainable alternative.
A word of warning: this book illustrates and gives information about biological control agents that may be unlicensed species in some countries. Some of these can be obtained on the Internet or from other sources. Purchasers of these should be aware that if unlicensed biocontrol agents are used, the purchaser is liable to a fine (currently £1,000 per offense in the UK).
This book was first published in 2003 and was twice reprinted. The second edition has been completely revised with a number of new photographs, additional pest and beneficial organisms, a new section on the practical aspects and application of biological control, and a final chapter that puts biological control in perspective.
The original idea for the book developed from a suggestion by Dr. Paul Jepson, now at Oregon State
University. The objective was to produce a handbook containing profiles and color photographs of as many examples of biological control organisms from as wide a global area as possible. We have continued with this theme in the second edition and have added further information to help the reader more fully understand the concepts and practice of biological control and integrated pest and disease management.
Descriptions of the biocontrol organisms are divided into four sections: species characteristics, including organism size, host food, and closely related species; life cycle; crop/ pest associations; and influences of growing practices. The section on crop/pest associations describes how and when the organism attacks its prey, the crops and environments in which it is likely to be found, and whether it is commercially available. The section on the influence of growing practices completes each profile by summarizing how growers can make best use of these natural enemies, and often makes mention of harmful, safe, and IPM-compatible pesticides.
Although all the organisms occur naturally in various parts of the world and several are commercially mass produced, many can only be found in their natural environment and usually close to their food sources. We therefore thought that a short section on the pests was essential, since all the natural enemies require a host for their survival. This handbook will be useful to advisors, extension officers, educators and research workers, and to all growers, whether amateur or professional, with an eye for the environment, no matter how large or small the area under production. Finally, we would like to make specific acknowledgments to Dr. Mike Copland and Dr. John Fletcher. Both have read the entire book and made many useful suggestions, Mike has also written the final chapter, which we feel improves the whole book.
Biological Control in Plant Protection