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Novel strategies to exploit existing natural infections: synergisms between baculoviruses and other toxins. - HH3101TX

Baculoviruses are pathogens that have been used as bioinsecticides in the field throughout the last century. They can be easily formulated in aqueous solution and applied using conventional spray equipment. The strains used in biocontrol only infect a very restricted number of species and while this is desirable in terms of low impact on other non-target species and the environment, it also restricts their agricultural use.
The aim of this project is to extend their use by exploring potential synergisms between baculoviruses and other toxins and pathogens. There are two principle reasons to believe why they could form synergistic associations. The first is that recent research in our laboratory has discovered that quiescent, symptomless baculovirus infections are common in caterpillars in the field, and that these quiescent infections retain the ability to cause full lethal infections when triggered. One key question is what agents or conditions will consistently trigger a quiescent baculovirus into a lethal infection. If reliable field triggers may be found, then these could be used to manipulate pathogen that is already present in the field. The second is that many pathogens and toxins (e.g. Bt, antifeedants) act by restricting growth or retarding development. This could act to extend the ‘window of vulnerability’ of many Lepidoptera to baculoviruses, as many species acquire resistance as they increase in size. We are particularly interested in synergistic ‘partners’, such as Bt, which have elements of host specificity themselves. The combination of baculovirus and synergistic partner would be lethal to the pest, but of low impact for non-target species.
The outcome of this research programme will be to provide novel pest control solutions that have minimal impact on non-target insects in the field, and are of low toxicity to vertebrates. This will contribute to the promotion of a sustainable, competitive and safe food chain, with reduced pesticide use. It will also contribute to the protection of the rural environment, and the enhancement of biodiversity in field margins. The strategies developed here would be compatible with integrated pest management (as promoted by Linking Environment and Farming, LEAF, and other bodies).

1. To investigate the potential of other pathogens & toxins to supress the host immune system and to trigger latent baculoviruses in populations of Brassica pests.
2. To investigate the potential impact of identified triggers on non-target Lepidopteran species likely to be found in field margins of Brassica crops.
3. To investigate synergistic/competitive interactions between baculoviruses and potential triggers in the laboratory and field.
4. To conduct short term field experiments to characterise the transmission dynamics of baculoviruses in the presence of other pathogens.
5. To develop current models of transmission to encapsulate pathogen interactions; and to use these to make qualitative predictions about control efficacy of pathogen combinations through the season.
6. To conduct 'whole growing season' experiments to test qualitative predictions about relative efficacy of pathogen combinations in the field.
Project Documents
• Final Report : Novel strategies to exploit existing natural infections: synergisms between baculoviruses and other toxins   (5177k)
Time-Scale and Cost
From: 2003

To: 2006

Cost: £279,503
Contractor / Funded Organisations
Centre for Ecology and Hydrology, Natural Environment Research Council
Biological Control              
Organic Farming              
Pest Control              
Pesticide use              
Sustainable Farming and Food              
Sustainable Production              
Fields of Study