© University of Greenwich

The dynamics of populations of pests or insect vectors of disease, are complex, making the prediction of outbreaks difficult. Mathematical modelling and computer simulation provide ways to help unravel such complex systems and understand how pests and vectors interact with the environment and with other organisms. Modelling approaches are used to ensure efficient use of resources in integrated pest management programmes, to predict the likely impact of new control measures, and to compare economic returns from different control strategies.

 

The Pest Systems Modelling Group works on a wide range of resource management problems particularly in developing countries. Areas of expertise include:

• Disease epidemiology
• Insect, weed and vertebrate population dynamics
• Multivariate and time-series analyses
• Biological control
• Pathogen-vector interactions
• Pesticide performance
• Expert systems, databases and bio-economics
• Risk analysis and impact assessment

Staff

Dr Johnson Holt
Prof. Robert Cheke

Projects

Spatial simulation model of rice tungro disease dynamics to evaluate control tactics (A0487, A0804)

Dynamics of insecticide resistance in Helicoverpa armigera populations.

Analyses of dynamics of Desert Locust plagues

Multivariate analyses of weed communities and their management in Mali Potential of Smicronyx for biological control of of Striga hermonthica.

Analytical model to understand epidemics of African cassava mosaic virus (A0936).

Analyses of onchocerciasis vector biting intervals Economic evaluation of control strategies for the African armyworm Spodoptera exempta.

Models to predict the optimal timing of fumigation intervals for control of stored product pests

Models to forecast outbreaks of migrant pests (locusts, armyworm and quelea birds) (Projects A1001, A1002)

Publications

© University of Greenwich

Smith M C, Valverde B, Merayo A, Fonseca J F (Draft in preparation) Integrated management of Rottboellia cochinchinensis in a maize based cropping system in Costa Rica: a modelling approach to exploring the options

Coyne D, Smith M C, Plowright (Submitted to Agriculture, Ecosystems and Environment) Plant parasitic nematode communities on upland and hydromorphic rice in West Africa: relationship with yield and moisture availability on a continuum slope.

Smith M C, Valverde B, Merayo A, Fonseca J F (Submitted to Weed Science) Integrated management of Rottboellia cochinchinensis in a maize-based cropping system in Costa Rica: modelling the impact of control tactics.

Jones, P. J., Cheke, R. A., Mundy, P. J., Dallimer, M. & Venn, J. F. (in press) Quelea populations and forecasting based in southern Africa. In Cheke, R.A., Rosenberg, L.J. & Kieser, M. (eds.) Proceedings of a Workshop on Research Priorities for Migrant Pests of Agriculture in Southern Africa, Plant Protection Research Institute, Pretoria, South Africa, 24-26 March 1999.

Venn, J. F., Ward, A. R., Smith, M. C., & Cheke, R. A., (in press) Fishloss - A database of post-harvest fish losses. To be published at; Workshop on Post-Harvest Fish Loss Assessment, 20-22 September 2000

Smith, M.C., Page, W.W., Holt, J. And Kytere, D. (2000) Spatial dynamics of maize streak virus disease epidemic development in maize fields. International Journal of Pest Management 46: 55-66.

Zhang, X-S. Holt, J. And Colvin, J. (2000) A general model of plant-virus disease infection to incorporate vector aggregation. Plant Pathology 49: 435-444.

Holt, J., Mushobozi, W.L., Tucker, M.R. & Venn, J. (2000) Modelling armyworm population dynamics to forecast outbreaks. Workshop on Research Priorities for Migrant Pests of Agriculture in Southern Africa, Plant Protection Research Institute, Pretoria, South Africa, 24-26 March 1999. (R. A. Cheke, L. J. Rosenberg and M. Kieser eds.) Chatham, UK: Natural Resources Institute. pp 151-163. ZHU, L-H.,

Holt, J. Black, R. (2000) New approaches to pest risk analysis for palnt quarantine. Proceedings of the British Crop Protection Conference - Pests and Diseases 2000. pp 495 - 498.

Kimmins, F. M., Green, S. V., Cheke, R. A., Gibson, G. P., Stevenson, P. & A Li, F. (1999) Transmission of rice yellow mottle virus by the chrysomelid beetle Trichispa sericea. Abstr. Proc. VIIth. Int. Plant Virus Epidemiology Symposium, Aguadula, Spain.

Tucker, M.R. And Holt, J. (1999) Decision tools for managing migrant insect pests In: Decision Tools for Sustainable Agriculture (I.F. Grant & C Sear, eds). Natural Resources Institute, Chatham, pp 97 - 122.

Naidu, R.A., Kimmins, F.M., Holt, J., Robinson, D.J., Deom, C.M. And Subrahmanyam, P. (1999) Spatiotemporal separation of groundnut rosette disease agents. Phytopathology 89: 934-941.

Holt, J., Colvin, J. And Muniappa, V. (1999) The dynamics of plant virus diseases with transitory vectors: implications for the control of tomato leaf curl virus in southern India. Journal of Applied Ecology 36: 1-10.

Holt, J. And Chancellor, T.C.B. (1999) Modelling the spatio-temporal deployment of resistant varieties to reduce the incidence of rice tungro disease in a dynamic cropping system. Plant Pathology 48: 453-461.

Zhang, X-S, Holt, J. And Colvin, J. (1999) Mathematical models of the dynamics of host plant infection by helper-dependent virus complexes: why are helper viruses always avirulent? Phytopathology 90: 85-93.

Grilli, M.P. And Holt, J. (1999) Vector feeding period variability in epidemiological models of persistent plant viruses. Ecological Modelling 126: 49-57.

Holt, J., Colvin, J. & Muniyappa, V. (1999) Identifying control strategies for tomato leaf curl virus disease using an epidemiological model. Journal of Applied Ecology 36: 625-633.

Page W W, Smith M C And Holt J (1999) The impact of intercrops on maize streak virus disease in maize. Annals of Applied Biology 135: 385-393.

Smith M C (1999) Modelos para evaluar el potencial con el cárbon, Sporisorium ophiuri, para controlar Rottboellia cochinchinensis. p137-156 In: Control biológico de Rottboellia cochinchinensis (Ed. Vera Sánchez Garita) Serie Técnica
No. 308.CATIE, Turrialba, Costa Rica.

Venn, J.F., Cheke, R. A., & Jones, P. J., (1999) Quelea Bird-Pest Database - Southern Africa Data. Ver 0.41n Published at; Workshop on Research Priorities for Migrant Pests of Agriculture in Southern Africa, Plant Protection Research Institute, Pretoria, South Africa, 24-26 March 1999.

Cheke, R., Ward, A.R. (1998), 'A model for evaluating interventions designed to reduce post-harvest fish losses', Fisheries Research 35: 219-227

Mccall, P. J., Cheke, R. A., Wilson, M. D., Post, R. J., Flook, P. K., Mank, R., Sima, A. & Mas, J. (1998) Distribution of the Simulium damnosum complex on Bioko island, Equatorial Guinea, and the potential for onchocerciasis elimination by vector eradication. Med. Vet. Ent. 12: 267-275.

Cheke, R., Wilson, M., Osei, M., Post, R.J. (1998), 'Effect of human activity and environmental change on vector/host/parasite distribution and epidemiology of onchocerciasis', British Simulium Group Bulletin 12: 2-4

Trumper, E.V. And Holt J. (1998) Modelling pest population resurgence due to re-colonisation of fields following an insecticide application. Journal of Applied Ecology 35: 273-285.

Jeger, M.J., Van Den Bosch, F., Madden, L.V. And Holt, J. (1998) A model for analysing plant-virus transmission characteristics and epidemic development. IMA Journal of Mathematics Applied in Medicine and Biology 15: 1-18.

Smith, M.C., Holt, J., Kenyon, L. And Foot, C. (1998) Quantitative epidemiology of banana bunchy top virus disease and its control. Plant Pathology 47: 177-187.

Smith, M.C. (1998), 'Models of a head smut epidemic in itchgrass: the potential for biocontrol', Abstracts of offered papers to International Conference Plant Pathology, 2.1.2, 2.6.

Cheke, R. A., Mccall, P. J. & Mas, J. (1997) The vector status of Simulium damnosum on the island of Bioko in Equatorial Guinea. Transactions of the Royal Society of Tropical Medicine and Hygiene 91: 153-154.

Holt, J. & Cheke, R. A. (1997) Modelling. pp. 351-378 in Dent, D.R. & Walton, M. P.(eds.) Methods in Ecological and Agricultural Entomology. CAB International, Wallingford, UK.

Ward, A. & Cheke, R. A. (1997) Modelling post-harvest fish losses. Aquaculture News 24: December 1997, pages 22-23.

 

Smith, M. C., Venn, J., Cheke, R. A. & Ward, A. R. (1997) A relational database of post-harvest fish losses. Naga, ICLARM Q. 20: 8-11.

Holt, J., Jeger, M.J., Thresh J.M. And Otim-Nape, G.W. (1997) An epidemiological model incorporating vector population dynamics applied to African cassava mosaic virus disease. Journal of Applied Ecology 34: 793-806.

Smith, M.C. And Holt, J. (1997) Analytical models of weed biocontrol with sterilizing fungi: the consequences of differences in weed and pathogen life-histories. Plant Pathology 46: 306-319.

Holt J. And Colvin, J. (1997) A differential equation model of the interaction between the migration of the Senegalese grasshopper, Oedaleus senegalensis, its predators and environmental carrying capacity. Ecological modelling 101: 185-193.

Holt, J. And Chancellor, T.C.B. (1997) Modelling plant disease dynamics in asynchronous cropping systems. Plant Pathology 46: 490-501.

Smith M C, Rutter J, Burt P J A, Ramirez F & Gonzalez O H (1997) Black Sigatoka disease of banana: spatial and temporal variability in disease development. Annals of Applied Biology 131: 63-77

Smith M C, Reeder R & Thomas M (1997) A model of the biological control of Rottboellia cochinchinensis with the head smut Sporisorium ophiuri. Journal of Applied Ecology 34: 388-398.

Smith M C & Holt J (1997) Analytical models of weed biocontrol with sterilizing fungi: the consequences of differences in weed and pathogen life-histories. Plant Pathology 46: 306-319.

Hodges, R.J., Smith, M., Madden, A., Russell, D., Gudrups, I. And Halid, H. (1997) Development of a decision support system for the fumigation of milled-rice bag-stacks in the tropics. Pp. 425-434 in: Proceedings of the International Conference on Controlled Atmosphere and Fumigation in Stored Products, Nicosia, Cyprus, 21-26 April 1996. Editors:
Donahaye, E.J., Navarro, S. and Varnava, A. Printco Ltd, Nicosia, Cyprus.

Cheke, R.A. & Holt, J. (1996) Chaos in desert locust plague dynamics? pp.42-45 In Walters, K. F. A. & Kidd, N. A. C., (Eds.) Populations and Patterns in Biology. IPPP, Ascot.

Holt, J. & Cheke, R. A. (1996) Réussites et échecs d'une règle simple de prévision des infestations du Criquet pèlerin au Sahel (Successes and failures of a simple predictive rule for desert locust infestations in the Sahel). Secheresse 7: 151-154.

Holt, J. And Cheke, R.A. (1996) Models of desert locust phase changes. Ecological modelling 91: 131-137.

Holt, J. And Chancellor, T.C.B. (1996) Simulation modelling of the spread of rice tungro virus disease: the potential for management by roguing? Journal of Applied Ecology 33: 927-936.

Holt, J., Chancellor, T.C.B. Reynolds, D.R., And Tiongco, E.R. (1996) Risk assessment for rice planthopper & tungro disease outbreaks. Crop Protection 15: 359-368.

Maddison, A.C., Holt, J. And Jeger, M.J. (1996). Spatial dynamics of a monocyclic disease in a perennial crop. Ecological Modelling 88: 45-52.

Colvin J. And Holt, J. (1996) A model to investigate the effects of rainfall, predation and egg quiescence on the population dynamics of the Senegalese grasshopper, Oedaleus senegalensis. Secheresse 7: 145-150.

Holt, J. And Cheke, R.A. (1996) Successes and failure of a simple predictive rule for desert locust infestations in the Sahel. Secheresse 7: 151-154.

Smith M C & Holt J (1996). Theoretical models for weed biocontrol: Rottboellia cochinchinensis infection with sterilising fungi. In: Moran VC , Hoffmann JH eds. Proceedings of the IX International Symposium on biological control of weeds, January 1996. Stellenbosch, South Africa: University of Cape Town, 319-325.

Webb M & Smith M C (1996) Biology of Striga hermonthica (Scrophulariaceae) in Sahelian Mali: effects on pearl millet yield and prospects for control. Weed Research 36: 203-212

Smith, M C & Webb M (1996)Estimation of the seed bank of Striga spp. [Scrophulariaceae] in Malian fields, and the implications for a model of biocontrol of Striga hermonthica. Weed Research 36: 85-92