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A desk study of current knowledge on the combined use of microbial biopesticides and chemical pesticides in Integrated Pest Management - PS2135

Over the next twenty to forty years, crop production will have to increase significantly to meet the needs of a rising human population. One way to increase food availability is to improve the management of pests. There are estimated to be around 67,000 different crop pest species - including plant pathogens weeds, and invertebrates - and together they cause about a 40% reduction in the world’s crop yield.

Since the 1950s, pest management in the UK and other industrialised countries has been based around the intensive use of synthetic chemical pesticides. However the use of synthetic pesticides as the mainstay of crop protection is becoming significantly more difficult due to a number of factors, including the evolution of resistance in target pest populations, and the withdrawal from sale of products based on ‘old’ chemistry because of new legislation.

A range of alternative pest management tactics is already available to farmers and growers including plant species or cultivars with resistance to or tolerance of pest attack, physical and cultural methods, natural compounds, and biological control with natural enemies. However the efficacies of these alternatives tend to be less or slower than that of fully effective conventional pesticides. Hence to make best use of alternative controls, they should be used in combination with minimnal use of pesticides in Integrated Pest Management. Adoption of IPM principles will become mandatory for farmers and growers in 2014 as part of new EU regulations. The new legislation gives a specific status to non-chemical and natural alternatives to conventional synthetic chemical pesticides and requires them to be given priority wherever possible.

Microbial biopesticides are mass-produced, commercial crop protection agents that use living microorganisms as the active substance. They are being used increasingly in the UK and EU for crop protection. However, in general, many microbial biopesticides do not perform as well as chemical pesticides and this is considered to be a barrier to their wider use. This project will be done as a desk study to investigate the joint use of synthetic chemical pesticides with microbial biopesticides. The areas for investigation in this project include: the effects of combined applications of microbial biopesticides and chemical pesticides on the control of invertebrate pests; the effects of combined applications of different types of microbial pesticides; identifying the theoretical principles that help determine the outcome of a biopesticide-pesticide or biopesticide-biopesticide interaction; and the use of microbial biopesticides to increase the susceptibility to chemical pesticides of resistant genotypes of pest species.

Potential benefits include the collation of the current state of knowledge, identification of gaps in knowledge for future research, potential methods for overcoming pesticide resistance problems, reduced pesticide usage, improved biopesticide performance and enhanced pest control.
The overall objective of this research is to write a review based on the scientific literature and on contacting other scientists to determine current knowledge about interactions between microbial biopesticides and synthetic chemical pesticides. Results from this research will be considered in relation to insect and mite pests for which pesticide resistance is of particular concern. Collation of current knowledge will inform the development of policies to make better use of biopesticides and pesticides within IPM for more effective and sustainable pest management.

The component objectives are as follows:

1. As a ground clearing exercise, summarise the different types of microorganisms currently being used as commercial microbial biopesticides. Summarise the current availability of microbial biopesticides in the UK and the EU.
2. Review the scientific literature on the effects of combined applications of microbial biopesticides and chemical pesticides on the control of invertebrate pests.
3. Review the scientific literature on the effects of combined applications of different microbial biopesticides (e.g. pathogenic fungi combined with pathogenic viruses) on the control of invertebrate pests.
4. Liaise with other scientists and IPM practitioners who are investigating / using combined applications of microbial biopesticides and chemical pesticides or combined applications of different microbial biopesticides.
5. Summarise the different types of interactions documented between microbial biopesticides and pesticides (e.g. synergism, additive effects, or inhibition) and between different microbial biopesticides. Identify the general principles (in terms of mechanisms of interaction) that help determine the particular outcome.
6. Review what is known about whether microbial biopesticides could be used to increase the susceptibility to chemical pesticides of resistant genotypes of pest species.
Project Documents
• FRP - Final Report : PS2135 final report   (305k)
• ANX - Annex : PS2135 appendix   (424k)
Time-Scale and Cost
From: 2010

To: 2011

Cost: £29,990
Contractor / Funded Organisations
Warwick - HRI, ADAS UK Ltd.
Biological Control              
Food Security              
Pest and Weed Control              
Pesticide use              
Plants and Animals              
Fields of Study
Pesticide Safety