People › Dr Toby Bruce
Prof Toby Bruce, Senior Research Scientist in the Biological Chemistry department at Rothamsted Research, has a background in Biology and a PhD in Chemical Ecology. His research focuses on host location in insects, alarm and sex pheromone signals and plant defence. He has 52 scientific publications which include high impact journals such as PNAS, Ecology Letters and Trends in Plant Science. As well as advancing fundamental aspects of insect host location, he devises strategies for utilising semiochemicals for insect pest management at the field level ranging from plant activators that switch on plant defence to pheromone monitoring systems. He is interested in finding new ways to protect crops from pests. He has obtained BBSRC and EU funding for crop protection related projects including one on transgenic wheat emitting aphid alarm pheromone (BB/G004781/1) and SCPRID funding for a new project on stemborer resistant maize that involves collaboration with ICRISAT and ICIPE in Kenya. He is convenor of the Association of Applied Biologists Biocontrol group and a Visiting Professor at the Univeristy of Greenwich Natural Resources Institute.
Principal Investigator› A novel monitoring and forecasting system for the integrated management of bean seed beetle Bruchus rufimanus
› Modelling and manipulation of plant-aphid interactions: A new avenue for sustainable disease management of an important crop in Africa
› SMART cereals for management of stemborer pests in staple cereals in Africa
Project Leader› A new generation of insect resistant GM crops: Transgenic wheat synthesising the aphid alarm signal
› Adaptation and dissemination of the Push Pull technology (ADOPT)
› Lawes Trust Studentship: Role of host volatiles in plant disease epidermiology with insect vectors
› Pesticide use and risk reduction in European farming systems with Integrated Pest Management: PURE
Member› Innovative approaches to pest management
Project LeaderExploring adaptive immunity in plants
In their struggle for life, plants strongly rely on inducible defense mechanisms. These defense responses become activated when a plant is attacked by harmful pathogens or insects. Induced defence involves a wide spectrum of different chemical and physical defence barriers, ranging from the induction of toxic metabolites that target the attacker's physiology, to cell wall appositions that prevent invasions by pathogenic fungi. Despite this diversity in defensive strategies, the inducible defense arsenal is not always sufficient to protect the plant against intrusion by pathogens and insects. This is why plants have evolved an additional, more sophisticated, defense system that allows them to fine-tune their inducible defense system. Interestingly, this induced resistance is not based on direct defence activation by the inducing agent, but on a faster and stronger activation of inducible defence mechanisms at the moment the plant is exposed to stress. This sensitization for defence is called "priming". Because priming allows the plant to adjust its inducible defence system to the environmental conditions, it can be regarded as a form of adaptive immunity. Interestingly, stimulation of the plant's adaptive immune system through priming has already been shown to yield broad-spectrum resistance with minimal reductions in plant growth and seed set. This suggests an important ecological function of plant adaptive immunity, which increases the plant's ability to survive in hostile environments.
Current insecticides are ineffective in reducing damage to bean crops by bean seed beetle, Bruchus rufimanus, resulting in loss of opportunity for growers in lucrative markets for human consumption due to crop rejection on standards of quality. Lack of precision in spray timing has resulted in increased applications, which in turn increases the risk of pesticide resistance. This project aims to develop a semiochemical-based monitoring system as part of an IPM strategy including resistant varieties. Effective control of bruchids is essential for growers to expand beans as a valuable break crop in both organic and conventional arable farming systems. Greater knowledge of the biology of the pest will allow more effective control with insecticides and a monitoring system will provide a reliable risk indicator and a means to determine the need or the optimum timing for sprays, reducing multiple applications and risk of resistance. Improvements in pesticide application will deliver more effective control and the identification of genetic resources of plant resistance for breeding programmes will enhance a package of IPM approaches to improve insecticide timing, reduce risk of resistance and ultimately reduce reliance on insecticides thus enabling sustainable bean production in the UK.
MemberAugmentation with synergists, of the effects of natural plant activators against pest aphids assessment
The aim of the project will be to optimise natural plant defence chemistry by applying a plant activator, whilst at the same time maximising the inhibition of the target insects’ defensive enzymes by the use of a synergist. A straight mixture of these two components may give the required effect on the insect, but it may be that the components will need to be applied separately, at different times, to achieve the optimum effect (temporal synergism). The different combinations of activator and synergist treatments will be tested, initially under laboratory conditions, against the grain aphid, Sitobion avenae, and the bird cherry-oat aphid, Rhopalosiphum padi on wheat. The study will then be extended to a field trial, where the most effective treatments will be tested against natural cereal aphid populations under field conditions, to demonstrate their potential for further investigation.
Chemical ecology is the study of interactions between organisms as mediated by naturally produced chemical signals (semiochemicals) that transmit information both within and between species. Semiochemicals act by non-toxic mechanisms and the project investigates how these can repel pest insects and attract their natural enemies. The project defines the biological occurrence and role of semiochemicals. It focuses on interactions of pest insects with their hosts and beneficial insects and how blends of volatiles are used for host recognition by insects as well as avoidance of non-hosts. Insect neurophysiology, particularly relating to olfaction, is used to study the basis of host location. Our pest targets are primarily phytophagous insects that damage crops but also include haematophagous insects of medical and veterinary significance. Advanced analytical and electrophysiological techniques are used to study semiochemicals at the very low levels produced by plants and insects and specialised bioassays determine their effects on insect behaviour and plant defence. Plant hosts of phytophagous insects are not passive victims and possess natural defence mechanisms that act directly against pests and indirectly by tritrophic interactions with predators and parasitoids. Thus plant defence can be induced or primed by treatment of plants with activator semiochemicals. Primed plants elicit accentuated and more rapid defence responses when subsequently attacked but defence is not constitutively upregulated. Semiochemicals are deployed in the field after preliminary studies in the laboratory. Strategies for utilising semiochemicals for insect pest management at the field level include switching on plant defence with plant activators, manipulation of host location cues in “push-pull” systems, deployment of aphid alarm pheromone signals and development of trapping systems based on attractive semiochemicals.Creating smallholder led growth through ‘push-pull’ technologies in Eastern Africa
Maize and sorghum are the principal food and cash crops for millions of the poorest people in eastern and southern Africa. However, stemborers and Striga weeds are two of the major biotic constraints to increased crop production in these areas. In a previous project we developed a simple and relatively inexpensive technology, the ‘push-pull’ strategy, that puts stemborer and Striga control within the reach of African farmers. This involves trapping stemborers on highly susceptible trap plants (pull) whilst driving them away from the maize crop using repellent inter-crops (push). The Striga control component is based on the use of inter-crops that act through a combination of mechanisms, including abortive germination of seeds that fail to develop and attach on the host. Plants, which repel stemborers and also inhibit and eliminate Striga, have also been identified. During the last five years, on-farm trials with more than 3,500 farmers in 15 districts of Kenya and 5 districts in Uganda have confirmed that these technologies are effective and have significant impacts on food security and income generation for resource-poor maize farmers.
The main objective of this project is to develop the most appropriate methods for delivering semiochemicals to the crop environment to achieve the intended effect on target plant-pest-natural enemy systems and to test for potential effects on non-targets. By influencing the colonisation of crop plants and subsequent pest population dynamics, semiochemicals can thereby be used to disrupt or direct pests away from the crop and attract them to areas where they can be controlled (the “push-pull” strategy). Semiochemicals act through behavioural mechanisms rather than by toxicity and thus offer benign means of crop protection with which to minimise, supplement, or in the long-term replace, use of broad-spectrum pesticides in Integrated Pest Management (IPM). To demonstrate effective manipulation of plant-pest-natural enemy systems, semiochemicals arising from the previous Defra programme (and in future PS2101), successful representative complexes (cereal aphids, oilseed rape beetles, pea and bean weevil and comparable aphids and dipterous stemborers or midges) will be used.
ENDURE aims to create a coordinated structure that takes advantage of alternative technologies, will build on advances in Agricultural Sciences, Ecology, Behaviour, Genetics, Economics and Social Sciences and will connect researchers with other stakeholders in extension, industry, policy-making and civil society. The multi-disciplinary and cross-sector approach aims to foster the development and implementation of strategies to rationalise and reduce pesticide inputs.
The main objective of this project is to develop a framework for the practical control of insect pests by means of semiochemicals. These are non-toxic, insect-produced (pheromones) or plant-derived chemicals that act as signals between organisms to cause natural behavioural or developmental changes in the recipient. As such, they can be used to manipulate populations of both pest and beneficial species and are perceived as a means of answering the demand for the reduction of intrinsically toxic materials in the environment.
The main objective of the proposed strategic research is to identify and provide semiochemicals, i.e. chemicals that control pest or natural enemy behaviour and development or act as signals to switch on defence effects in plants, as alternatives to conventional pesticides. By influencing the colonisation of crop plants and subsequent pest population dynamics, semiochemicals can thereby be used to disrupt or direct pests away from the crop and attract them to areas where they can be controlled (the “push-pull” strategy). Semiochemicals act through behavioural mechanisms rather than by toxicity and thus offer benign means of crop protection with which to minimise, supplement, or in the long-term replace, use of broad-spectrum pesticides in Integrated Pest Management (IPM). Chemically-based interactions between plants and other plants or microorganisms can similarly suppress weeds or diseases. In lower input systems, including organic farming, the use of semiochemicals complements the greater exploitation of biological control agents, selective pesticides and pest-resistant cultivars.
The orange wheat blossom midge came to prominence in 1993 when a widespread outbreak caused much damage to UK crops. Farmers and agronomists have difficulty in assessing risk in the field and in consequence often adopt a prophylactic approach to control, treating around 200,000 ha each year. Such treatment may be poorly targeted, failing to obtain effective control and having an unnecessary impact on the environment.
This project will establish the science underpinning our recent discovery that soaking seeds of plants in plant defence hormones confers long-lasting pest resistance in plants grown from these seeds. It will investigate the fundamental mechanisms behind priming of defence against pests and diseases by seed treatments with jasmonic acid (JA) and the nonprotein amino acid, beta-aminobutyric acid (BABA). The primary objectives are:
1. Quantify the marginal social and economic benefits of a reduction in the use of pesticides in UK cereal systems .
Hegde, M., Oliveira, J.N., da Costa, J.G., Loza-Reyes, E., Bleicher, E., Santana, A.E.G., Caulfield, J.C., Mayon, P., Dewhirst, S.Y., Bruce, T.J.A., Pickett, J.A., Birkett, M.A. (2012) Aphid antixenosis in cotton is activated by the natural plant defence elicitor cis-jasmone. Phytochemistry 78: 81-88.
Jayanthi, P.D.K., Woodcock, C.M., Caulfield, J., Birkett, M.A., Bruce, T.J.A. (2012) Isolation and Identification of Host Cues from Mango, Mangifera indica, That Attract Gravid Female Oriental Fruit fly, Bactrocera dorsalis. J. Chem. Ecol. 38: 361-369.
Pickett, J.A., Ardottir, G.I., Birkett, M.A., Bruce, T.J.A., Chamberlain, K., Khan, Z.R., Midega, C.A.O., Smart, L.E., Woodcock, C.M. (2012) Aspects of insect chemical ecology: exploitation of reception and detection as tools for deception of pests and beneficial insects. Physiol. Entomol. 37: 2-9.
Tamiru, A., Bruce, T.J.A., Midega, C.A.O., Woodcock, C.M., Birkett, M.A., Pickett, J.A., Khan, Z.R. (2012) Oviposition Induced Volatile Emissions from African Smallholder Farmers' Maize Varieties. J. Chem. Ecol. 38: 231-234.
Yu, X.-D., Pickett, J., Ma, Y.-Z., Bruce, T., Napier, J., Jones, H.D., Xia, L.-Q. (2012) Metabolic Engineering of Plant-derived (E)-β-farnesene Synthase Genes for a Novel Type of Aphid-resistant Genetically Modified Crop Plants. Journal of Integrative Plant Biology 54: 282-299.
Luna E, Bruce TJA, Roberts MR, Flors V and Ton J (2012) Next Generation Systemic Acquired Resistance. Plant Physiol. 158: 844-853.
Lebesa, L.N., Khan, Z.R., Krueger, K., Bruce, T.J.A., Hassanali, A., Pickett, J.A. (2012) Farmers' knowledge and perceptions of blister beetles, Hycleus spp. (Coleoptera: Meloidae), as pest herbivores of Desmodium legumes in western Kenya. Int. J. Pest Manage. 58: 165-174.
Bruce TJA (2012) GM as a route for delivery of sustainable crop protection. J. Exp. Bot. 63: 537-541. http://dx.doi.org/10.1093/jxb/err281
Tamiru A, Bruce TJA, Woodcock CM, Caulfield JC, Midega CAO, Ogol CKPO, Mayon P, Birkett MA, Pickett JA, Khan ZR (2011) Maize landraces recruit egg and larval parasitoids in response to egg deposition by a herbivore. Ecology Letters 14: 1075-1083. http://dx.doi.org/10.1111/j.1461-0248.2011.01674.x
Bruce TJA & Pickett JA (2011) Perception of plant volatile blends by herbivorous insects – Finding the right mix. Phytochemistry 72: 1605–1611. http://dx.doi.org/10.1016/j.phytochem.2011.04.011
Lebesa LN, Khan ZR, Hassanali A, Pickett JA, Bruce TJA, Skellern M and KrÜGer K, Responses of the blister beetle Hycleus apicicornis to visual stimuli. Physiol Entomol. 36: 220-229.
Björkman M et al. (2011) Phytochemicals of Brassicaceae in plant protection and human health – Influences of climate, environment and agronomic practice. Phytochemistry, 72: 538-556.
Tamiru A, Getu E, Jembere B & Bruce TJA (2011). Effects of temperature and relative humidity on the development and fecundity of Chilo partellus (Swinhoe) (Lepidoptera: Crambidae). Bull. Entomol. Res. 102: 9-15.
Bruce TJA, Martin JL, Smart LE, Pickett JA (2011) Development of semiochemical attractants for monitoring bean seed beetle, Bruchus rufimanus. Pest Management Science doi: 67: 1303-08
Hedge M, Oliveira JN, da Costa JG, Bliecher E, Santana AEG, Bruce TJA, Caulfield J, Dewhirst SY, Woodcok CM, Pickett JA, Birkett MA (2011) Identification of Semiochemicals Released by Cotton, Gossypium hirsutum, Upon Infestation by the Cotton Aphid, Aphis gossypii. J. Chem. Ecol. 37: 741-750.
Matthes MC, Bruce TJA, Chamberlain K, Pickett JA, Napier JA (2011) Emerging roles in plant defense for cis-jasmone-induced cytochrome P450 CYP81D11 Plant Signalling and Behavior 6: 563 - 565
Khan ZR, Midega CAO, Pittchar J, Pickett JA, Bruce TJA (2011) Push-pull technology: a conservation agriculture approach for integrated management of insect pests, weeds and soil health in Africa. International Journal of Agricultural Sustainability 1: 162-170
Oluwafemi S, Bruce TJA, Pickett JA, Ton J & Birkett MA (2011) Behavioral Responses of the Leafhopper, Cicadulina storey China, a Major Vector of Maize Streak Virus, to Volatile Cues from Intact and Leafhopper-Damaged Maize. J. Chem. Ecol. 37: 40-48
Padmaja PG, Woodcock CM, Bruce TJA (2010) Electrophysiological and Behavioral Responses of Sorghum Shoot Fly, Atherigona soccata, to Sorghum Volatiles. J. Chem. Ecol. 36: 1346-1353
Birkett, M.A., Bruce, T.J.A. and Pickett, J.A. (2010) Repellent activity of Nepeta grandiflora and Nepeta clarkei (Lamiacease) against the cereal aphid, Sitobion avenae (Homoptera: Aphididae). Phytochemistry Letters 3: 139-142
Matthes M, Pickett JA, Bruce TJA, Ton J & Napier (2010) The transcriptome of cis-jasmone induced resistance in Arabidopsis thaliana and its role in indirect defence. Planta 232: 1163-80
Khan ZR, Midega CAO, Bruce TJA, Hooper AM & Pickett JA (2010) Exploiting phytochemicals for developing a ‘push–pull’ crop protection strategy for cereal farmers in Africa. J Exp. Bot. 61: 4185-4196
Bruce TJA (2010) Tackling the threat to food security caused by crop pests in the new millennium. Food Security 2: 133-141
Bruce TJA, Midega CAO, Birkett MA, Pickett JA & Khan ZR (2010) Is quality more important than quantity? Insect behavioural responses to changes in a volatile blend after stemborer oviposition on an African grass. Biology Letters 6: 314-317
Bruce TJA, Smart LE & Pickett (2010) Insect pests of wheat: a worldwide perspective. In “The World Wheat Book – a history of wheat breeding – vol 2” Eds. A Bonjean, W Angus & M van Ginkel, Lavoisier, Paris.
Bruce TJA (2010) Exploiting plant signals in sustainable agriculture. In “Plant Communication from Ecological Perspective” Eds. Velemir Ninkovic & František Baluška Ch 12. Springer-Verlag, Berlin Heidelberg.
Webster B, Bruce TJA, Hardie J & Pickett JA (2010) Volatiles functioning as host cues in a blend become non-host cues when presented alone to the black bean aphid. Animal Behaviour 79: 451-457 http://dx.doi.org/10.1016/j.anbehav.2009.11.028
Webster B, Gezan S, Bruce TJA, Hardie J & Pickett JA (2010) Between plant and diurnal variation in quantities and ratios of volatile compounds emitted by Vicia faba plants. Phytochemistry 71: 81-89 http://dx.doi.org/10.1016/j.phytochem.2009.09.029
Ukeh DA, Birkett MA, Bruce TJA, Allan EJ, Pickett JA, Mordue AJ (2009) Behavioural responses of the maize weevil, Sitophilus zeamais, to host (stored-grain) and non-host plant volatiles. Pest Management Science http://dx.doi.org/10.1002/ps.1828
Midega, C. A. O., Khan, Z. R., Van den Berg, J., Ogol, C. K. P. O., Bruce, T. J., Pickett, J. A. (2009) Non-target effects of the `push-pull' habitat management strategy: parasitoid activity and soil fauna abundance. Crop Prot. 28: 1045-1051.
Mendesil, E., Bruce, T., Woodcock, C., Caulfield, J., Seyoum, E. and Pickett, J. Semiochemicals used in Host Location by the Coffee berry Borer, Hypothenemus hampei. J. Chem. Ecol. 35: 944 - 950.
Whitney HM, Chittka L, Bruce TJA, Glover BJ (2009) Conical epidermal cells allow bees to grip flowers and increase foraging efficiency. Curr. Biol. 19: 948-953.
Bruce TJA, Smart LE (2009) Orange wheat blossom midge, Sitodiplosis mosellana, management. Outlooks Pest Manag. 20: 89-92.
Webster B, Bruce TJA, Pickett JA & Hardie J. (2008) Olfactory recognition of host plants in the absence of host-specific volatile compounds: Host location in the black bean aphid, Aphis fabae. Communicative & Integrative Biology 1: 167-169.
Webster B, Bruce TJA, Dufour S, Birkemeyer C, Birkett MA, Hardie, J & Pickett, JA (2008) Identification of volatile compounds used in host location by the black bean aphid, Aphis fabae. J. Chem. Ecol. 34: 1153-1161.
Bruce TJA, Matthes M, Chamberlain K, Woodcock CM, Mohib A, Webster B, Smart LE, Birkett MA, Pickett JA & Napier J (2008) cis-Jasmone induces Arabidopsis genes that affect the chemical ecology of multritrophic interactions with aphids and their parasitoids. PNAS 105: 4553-4558.
Bruce TJA, Matthes MC, Napier JA, & Pickett JA (2007) Stressful ï¿½memoriesï¿½ of plants: evidence and possible mechanisms. Plant Sci. 173: 603-608.
Bruce TJA & Pickett JA (2007) Plant defence signalling induced by biotic attacks. Curr. Opin. Plant Biol. 10: 387-392.
Bayram A, Gultekin A, Bruce TJ & Gezan, S (2007) Factors associated with mortality of the overwintering generation of Sesamia nonagrioides under field conditions Phytoparasitica 35: 490-506.
Bruce TJA, Hooper AM, Ireland LA, Jones OT, Martin JL, Smart LE, Oakley J & Wadhams LJ (2007) Development of a pheromone trap monitoring system for orange wheat blossom midge, Sitodiplosis mosellana, in the UK. Pest Manag. Sci. 63: 49-56.
Beale MH, Birkett MA, Bruce TJA, Chamberlain K, Field LM, Huttly AK, Martin JL, Parker R, Phillips AL, Pickett JA, Prosser IM, Shewry PR, Smart LE, Wadhams LJ, Woodcock CM & Zhang Y (2006) Aphid alarm pheromone produced by transgenic plants affects aphid and parasitoid behavior. PNAS 103: 10509-13.
Pickett JA, Bruce TJA, Chamberlain K, Hassanali A, Khan ZR, Matthes MC, Napier JA, Smart LE, Wadhams LJ & Woodcock CM (2006) Plant volatiles yielding new ways to exploit plant defence. In ï¿½Chemical Ecology: from Gene to Ecosystem.ï¿½ Eds. M Dicke & W Takken. Springer, Wageningen, The Netherlands. Ch. 11. pp. 161-173.
Bruce TJA, Birkett MA, Blande J, Hooper AM, Martin JL, Khambay B, Prosser I, Smart LE & Wadhams LJ (2005) Response of economically important aphids to components of Hemizygia petiolata essential oil. Pest Manag. Sci. 61: 1115-1121.
Bruce TJA, Wadhams LJ & Woodcock CM (2005) Insect host location: a volatile situation. Trends Plant Sci. 10: 269-274.
Birkett MA, Bruce TJA, Martin JA, Smart LE, Oakley J & Wadhams, LJ (2004). Responses of female orange wheat blossom midge, Sitodiplosis mosellana, to wheat panicle volatiles. J. Chem. Ecol. 30: 1319-1328
Bruce TJA, Martin JL, Pickett JA, Pye BJ, Smart LE & Wadhams LJ (2003) cis-Jasmone treatment induces resistance in wheat plants against the grain aphid, Sitobion avenae (Fabricius) (Homoptera: Aphididae). Pest Manag. Sci. 59: 1031 - 1036
Bruce TJA, Pickett JA & Smart LE (2003) cis-Jasmone switches on plant defence against insects. Pesticide Outlook 14: 96 - 98
Bruce, TJ & Cork, A (2001) Electrophysiological and behavioral responses of female Helicoverpa armigera (Lepidoptera, Noctuidae) to compounds identified in flowers of African marigold, Tagetes erecta. J. Chem. Ecol. 27: 1119 - 1131
› Visiting Professor: Natural Resources Institute, University of Greenwich
› Visting Lecturer at the University of Nottingham
› Convenor of Association of Applied Biologists (AAB) Biocontrol Group
› Association of Applied Biologists Biocontrol Committee: Full Committee Member
› Invited lecture: European Chemoreception Research Organisation conference (ECRO 2011): Insect perception of blends of host plant volatiles
› Keynote talk: University of Amsterdam, Workshop on Plant-Insect Interactions: Responses of phytophagous insects and their natural enemies to plant volatile profiles
› Invited Lecture: Crop World Global 2011: Examining recent research into aphid-resistant GM wheat
› Invited Lecture: AAB-IBMA Biopesticides 2011: The role of pheromones and other semiochemicals in IPM programmes
› Invited lecture: Crop World Global 2010: Responding to the threat to food security caused by crop pests in the new millennium.
› Session chairman at conference: Organised and chaired a session on biotic interactions at the AAB conference, Agriculture: Africa's "Engine for Growth" - Plant science & biotechnology hold the key.
› Reviewer for Journals: Agricultural and Forest Entomology
Annals of Applied Biology
Bulletin of Entomological Research
Entomologia Experimentalis et Applicata
International Journal of Tropical Insect Science
Journal of Chemical Ecology
Journal of Experimental Botany
Pest management science
Plant, Cell & Environment
› Conference organiser and chairman: Organised and chaired a Society of Chemistry and Industry conference on Plant Signalling
› PhD supervisor: PhD Supervision - Ben Webster (successfully completed in 2009)
Operates two national networks for monitoring insect populations in the UK. More...
Provides the research community access to a range of in situ state-of-the-art instrumentation in hydrologically isolated fields and farms to better address key issues in sustainable agriculture. More...
A database of interactions between pathogens and their hosts maintained at Rothamsted Research with international input. More...
These have been running since the mid 19th Century, provide a unique experimental system and archive of soil and plant samples. More...
Rothamsted Research receives
strategic funding from the BBSRC
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