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Contact Address: Lancaster Environment Centre,
2011 - present EU Marie Curie Fellow Sydney University/Lancaster University
Research: Collective motion, nutrition-pathogen interactions
2008 - 2011 Senior Research
Research: Molecular ecology of insect-microbe interactions
2007 - 2008 Postdoctoral Fellow CSIRO Entomology,
Research: Ecology of fungal pathogens and mosquitoes
2005 - 2007 Postdoctoral Fellow
Research: Microbe-insect interactions
2002 - 2005 PhD Studentship NERC
Research: Molecular ecology of insect viral-pathogens
2001 - 2002 Research Assistant NERC CEH
Research: Molecular biology of insect baculoviruses
1996 - 1999 BSc (Hons) Zoology (2.1)
Society of Invertebrate Pathology
British Ecological Society
IOBC - WPRS
2010 Marie Curie International Outgoing Fellowship EU
The role of natural-enemies in regulating migratory agricultural pests, €268,824
Faculty Research Grant, Lancaster University.
Sickly sand-martins: carriers of an emerging infectious disease? £800
International Travel Grant, Lancaster University. £940
2009 Faculty Research Grant, Lancaster University.
Emerging diseases: the menace of the shrew, £950
2008 Small Grant Scheme, Lancaster University.
Microsatellite development for migratory pest populations, £6000
2005 Student Travel Prize, Society of Invertebrate Pathology. US$500
1. Nutrition, collective motion and immunity - disease dynamics in migratory insects
A key principle in the evolutionary ecology of disease is the degree to which hosts invest in defence against parasites and pathogens. Established concepts in this area include (1) that disease risk is a function of host density and (2) that risk of disease leads to selection on the host to minimize the potential costs of disease. A clear prediction that arises from these concepts is that hosts living at high densities should invest more in defence than those living at low densities: a hypothesis known as “positive density-dependent prophylaxis” (DDP). For the past three years I have studied the African armyworm system (Spodoptera exempta), a devastating crop pest which expresses an extreme form of density-dependent phenotypic plasticity positive-DDP in response to host crowding. An equally destructive agricultural pest, the Australian Plague Locust (APL), Chortoicetes terminifera, has been suggested to exhibit “negative-DDP”, with certain key immune functions shown to be lower in gregarious than in the solitary insects. This project will attempt to determine why species with similar migratory activity appear to have evolved contrary behavioural and immunological strategies to combat disease transmission. The APL is an ideal model system to study the effects of crowding and migration, occurring in a socio-politically stable continent, allowing state-of-the-art field and laboratory experimentation. I will use my knowledge of migratory host-pathogen dynamics and expertise in experimental biology to investigate three main objectives, a) to determine the spatial and temporal pattern of natural disease epizootics in APL populations, b) to compare immune function and disease resistance in gregarious and solitary locusts, and c) to quantify the impact of protein availability on immune function, host behaviour and disease resistance. This research will contribute to the knowledge-base in global food security and nutrition biology. I will spend two years based at the University of Sydney, Australia, working in the lab of Professor Stephen Simpson FAA, and will then return to Lancaster to work again in iPEG with Ken.Photographs showing typical APL outbreaks. A: view of crop destruction and locust density (©State of New South Wales, 2005) B: landscape view of a locust marching-band, moving from left to right (©Brad Hazel, LHPA Forbes)
Spatial and temporal interactions between the African
armyworm and a viral pathogen
The African armyworm Spodoptera exempta is one of the most devastating crop pests in Africa, with the caterpillar stage of the moth being a major defoliator of staple crops, such as maize, wheat, sorghum, millet and rice, as well as pasture grasses. In East Africa, armyworm outbreaks (high-density aggregations of feeding caterpillars) are considered a serious problem in 9 out of 10 years, and in major outbreak years, armyworm can affect millions of hectares of farmland.
Our current project will explore the ecology of the SpexNPV virus and its wider role in the population dynamics of armyworm, with a view to determining how best to exploit the virus as a strategic biocontrol agent. Find out more at the ARMYWEB website.
|3. The use of
for the control of mosquito disease-vectors
The use of Metarhizium anisopliae and Beauveria bassiana fungi for the control of Aedes spp. and Anopheles spp. mosquitoes has great potential. During my time at CSIRO, I looked into the efficacy of using fungal formulations to control adult Aedes aegypti mosquitoes, the main vector species aiding the spread of Dengue Fever. From an initial screen of over 100 fungal isolates, 20 suitable isolates were identified for testing at in-vivo level. Firstly, a basic bioassay protocol was carried out at 26°C to identify the most virulent fungal isolates for the control of Ae. aegypti. Isolates of B. bassiana were generally found to be more virulent than M. anisopliae strains. More complex experiments investigating environmental factors and interactions with the dengue virus are currently being carried out. All this work has been undertaken in collaboration with Dr Jon Darbro (Queensland Institute of Medical Research) and Prof Matt Thomas (Penn State University).
Using baculoviruses as an effective control measure for forest pests
An industrial partner (Sylvar Technologies Inc.) is taking the lead to sequence a nucleopolyhedrovirus (OrleNPV) from the white-marked tussock moth Orgyia leucostigma (Lepidoptera: Lymantriidae). This virus is being developed as a potential biocontrol agent for use in eastern Canada.
Natural populations of the western spruce budworm, Choristoneura occidentalis (Lepidoptera: Tortricidae), have been surveyed for the presence of pathogens. The budworm is a serious defoliator of commercially important wood stands and a number of outbreaking populations have been reported from British Columbia in recent years. Three different virus species have been isolated, including a cypovirus, a nucleopolyhedrovirus and a granulovirus. This work has interesting implications for the natural dynamics of C. occidentalis populations, but also in developing a potential biocontrol agent against this forest pest species. This work has been undertaken with Dr Renee Lapointe (Sylvar Technologies Inc.) and Dr Chris Lucarotti (Canadian Forest Service).
Multiple-pathogen interactions in natural lepidopteran populations
Geographically separate populations of the univoltine winter moth (Operophtera brumata L) were sampled in heather habitats upon Orkney, to investigate the prevalence of four viral pathogens, and to evaluate their impact upon host lepidopteran populations. A nucleopolyhedrovirus (OpbuNPV) was prevalent, with two populations suffering viral mortality at rates of over 50%.
Three novel species of reovirus were detected - two within the Cypovirus genus (CPV). The third reovirus was isolated from both the winter moth and a hymenopteran parasitoid wasp, Phobocampe tempestiva, identified as a member of the genus Idnoreovirus.
Transmission strategies for all four virus species was investigated, looking into the role of vertical transmission, parasitoid vectoring and the presence of other lepidopteran host species. It is believed that a number of strategies combine to allow such pathogens to persist in a univoltine host. The relationship and interactions between the NPV and the CPV were investigated, as well as the likely impact of viral pathogens on host lepidopteran population dynamics. It was found that reovirus prevalence had a significantly negative impact on host female fecundity. This project has provided a valuable insight into the interactions of pathogens and parasitoids in the regulation of non-pest lepidopteran populations. This research was undertaken in collaboration with Prof Rosie Hails (CEH Oxford), Prof Bob Possee (CEH Oxford), Dr Steve Sait (Leeds University) and Prof Peter Mertens (IAH Pirbright).
Graham, R.I., Zhang, J., Morin, B., Lapointe, R., Nealis, V.G. and Lucarotti, C.J. 2010. Isolation and molecular characterization of baculoviruses from field populations of the western spruce budworm Choristoneura occidentalis (Lepidoptera: Tortricidae). Proceedings of the Spray Efficacy Research Group-International 2010. p. 73-79.
Zhang, J., Graham, R.I., Zahner, V., McIntosh, D. and Lucarotti, C.J. 2010. Microbiota associated with field-collected populations of pine false webworm, Acantholyda erythrochephala (Hymenoptera: Symphyta). Proceedings of the Spray Efficacy Research Group-International 2010, p. 45-49.
Graham, R.I., Grzywacz, D., Mushobozi, W.L., Cory, J.S., Shirras, A.D., Tummala, Y., Wilson, K. 2009. Using African armyworm NPV as a strategic biological control agent: will studying pathogen ecology provide the answers? The IOBC/WPRS Bulletin, vol. 45, 91-94.
Graham, R.I., Morin, B., Lapointe, R., Nealis, V.G., Lucarotti, C.J. 2009. Viral pathogens of the western spruce budworm, Choristoneura occidentalis. Proceedings of the Spray Efficacy Research Group-International 2009, p. 89-91.
Graham, R.I., Zahner, V., Lucarotti, C.J. 2008 Microbiota associated with field-collected populations of sawflies (Hymenoptera: Symphyta). Proceedings of the Spray Efficacy Research Group-International 2008, p. 66-67.
Possee, R.D., Graham, R.I., Burden, J.P., King, L.A., Hails, R.S. 2007. Persistent virus infections in laboratory and field insect populations: fact or myth? The IOBC/WPRS Bulletin, vol. 31, 11-17.
Graham, R.I., Lucarotti, C.J. 2007. Microbial endosymbiosis in the pine false webworm and other forest pest insects. Proceedings of the Spray Efficacy Research Group-International 2007, p.72-73
Darbro, J.M., Graham, R.I., Kay, B.H., Ryan, P.A., Thomas, M.B. 2011. Evaluation of entomopathogenic fungi as potential biological control agents of the dengue mosquito, Aedes aegypti (Diptera: Culicidae). Biocontrol Sci.Techn. in press
Graham, R.I., Hartley, L., Wilson, K. 2011. Characterisation of a nucleopolyhedrovirus and Spiroplasma sp. bacterium associated with outbreaking populations of the Antler moth Cerapteryx graminis. J. Invertebr. Pathol. 107, 90-93
Graham, R.I., Mainwaring, M.C., du Feu, R. 2010. Detection of Rickettsia spp. from bird ticks in the United Kingdom. Med Vet Entomol 24, 340-43
Graham, R.I., Zahner, V., Lucarotti, C.J. 2008. An intracellular symbiont and other microbiota associated with field-collected populations of sawflies (Hymenoptera: Symphyta). Can. J. Microbiol. 54, 758–768
Graham, R.I., Morin, B., Lapointe, R., Nealis, V., Lucarotti, C.J. 2008. Molecular characterisation of a cypovirus isolated from the western spruce budworm Choristoneura occidentalis. Arch. Virol. 153, 1759-63
Graham, R.I., Rao, S., Hails, R.S., Sait, S.M, Attoui, H., Mertens, P.P.C., Possee, R.D. 2008. Sequence analysis of a reovirus isolated from the winter moth Operophtera brumata (Lepidoptera: Geometridae) and its parasitoid Phobocampe tempestiva (Hymenoptera: Ichneumonidae). Virus Res. 135, 42-47.
Graham, R.I., Rao, S., Hails, R.S., Sait, S.M., Mertens, P.P.C., Possee, R.D. 2007. Characterisation and sequence analysis of two novel cypoviruses isolated from the winter moth Operophtera brumata (Lepidoptera: Geometridae). Virus Genes 35, 463-471.
Whittome, B., Graham, R.I., Levin, D.B. 2007. Preliminary examination of gut bacteria from Neodiprion abietis (Hymenoptera: Diprionidae) larvae. J. ent. Soc. Ont. 138, 49-63.
Lucarotti, C.J., Morin, B., Graham, R.I., Lapointe, R. 2007. Production, application and field performance of Abietiv™, the balsam fir sawfly nucleopolyhedrovirus. Virolog. sinica 22, 163-172
Graham, R.I., Rao, S., Possee, R.D., Sait, S.M., Mertens, P.P.C., Hails, R.S., 2006. Detection and characterisation of three novel species of reovirus (Reoviridae), isolated from geographically separate populations of the winter moth Operophtera brumata (Lepidoptera: Geometridae) on Orkney. J. Invertebr. Pathol. 91, 79-87.
Graham, R.I., Tyne, W.I., Possee, R.D., Sait, S.M., Hails, R.S. 2004. Genetically variable nucleopolyhedroviruses isolated from spatially separate populations of the winter moth Operophtera brumata (Lepidoptera: Geometridae) in Orkney. J. Invertebr. Pathol. 87, 29-38.