Biopesticides for the control of storage insect pests

Abstract

The UK grain industry stores many tonnes of grain each year. Currently, chemical insecticides are used to protect this grain from infestation by stored product insects and mites. Only a limited number of products are available for application and there are concerns about safety, resistance and environmental impact of these conventional pesticides. In principle, the biological control of storage pests could overcome these problems. A previous LINK funded project (LK0914) established the potential for biological control of storage pests in the UK, using an insect-specific fungus Beauveria bassiana. The current project (LK0967) has investigated ways to increase the efficacy of the fungus and has also undertaken research to establish that mass production of high quality conidia (asexual spores) is possible, to ensure that formulations have a good shelf-life and has sought feedback from stakeholders with regard to this novel control method.

The work has concentrated on two different fungal isolates, both of which were found from insects in UK grain stores. The main objectives of the current project were:

1. To improve the efficacy of the insect-specific fungi when in contact with insects.
2. To improve the delivery of the insect-specific fungus to the insects.
3. To ensure the consistency and the safety of the product.
4. To ensure that the biopesticide product has wide acceptability and is effective under practical use.

Optimisation of production methods, formulation and delivery systems has resulted in prototype formulations that have good efficacy against a range of storage insect pests under conditions that are likely to be found in UK grain stores. Valuable information on the viability and efficacy of a range of formulation types was obtained, together with studies on the likely effect of the formulations on insect behaviour. Pilot scale trials using three species of stored product beetle have shown that significant levels of control can be achieved. Successful mass production of the conidia is necessary if the biopesticide is to be considered at a commercial level. This project has developed methods to ensure that mass production of the conidia at an industrial scale is possible. During the course of the project, the views of stakeholders and end-users were sought.

Specific concerns were addressed and the feedback was used to focus the research aims. The registration and safety issues for the use of a biopesticide were also studied. This project has made a significant contribution to the development of a biopesticide as a structural treatment for grain storage areas in the UK.