The role of endosymbionts and parasitoids in the structure and dynamics of insect-plant-pathogen associations
Our interests lie in the complex ecological associations which exist between insects such as aphids, which are capable of transmitting pathogenic micro-organisms to plants, and the endosymbiotic (parasitic?) bacteria and insect parasitoids which interact with them. A particular focus of this interest is the way in which plant nutritional state, endosymbiont profile, and attack by parasitoids act separately or together to influence the efficiency with which aphids vector plant pathogenic viruses.
There is accumulating evidence that endosymbiont bacteria may have complex effects on the efficiency with which pathogenic plant viruses are transmitted. Aphids harbour a “primary” endosymbiont in the genus Buchnera, which synthesises certain nutritionally important amino acids, and without which the aphid will usually die. In addition to Buchnera there may be a variable complement of “secondary” endosymbionts, whose role is much less clear, but which almost certainly have significant fitness effects on the aphid host and consequently its efficiency in vectoring plant viruses, and the emphasis of our research in the immediate future will be to tease apart and quantify these complex trophic interactions
Our experimental and field work is complemented by a parallel programme aimed at developing novel mathematical models to describe the dynamics of such systems, and especially the dynamics of the plant disease as influenced by the other members of the trophic association. A particular aim of the experimental programme is to enable us to parameterise these models accurately so that the longer term dynamics of the system can be reasonably investigated.
Fytrou, A., Kraaijeveld, A.R., Schofield, P.G., & Hubbard, S.F. (2006) Wolbachia infection suppresses both host defence and parasitoid counter-defence Proc. Roy. Soc. B 273; 1588, 791-797.
Pearce, I.G., Chaplain, M.A.J., Schofield, P.G., Anderson, A.R.A. & Hubbard, S.F. (2006) Modelling the spatio-temporal dynamics of multi-species host-parasitoid interactions: heterogeneous patters and ecological implications. Jour. Theoretical Biology 241, 876-886
Preedy, K., Schofield, P.G., Chaplain, M.A.J. and Hubbard, S.F. (2007). Disease induced dynamics in host-parasitoid systems; chaos and coexistence. Journal of the Royal Society Interface 4, 463-471.
Preedy, K. Schofield, P.G., Chaplain, M.A.J. and Hubbard, S.F. (2010). Disease induced dynamics in host-parasitoid systems; parasitoid vectored host infection. Journal of Theoretical Biology 262; 441-451
Clark, E.L., Karley, A.J. & Hubbard, S.F. (2010) Insect symbionts: manipulators of insect herbivore trophic interactions? Protoplasma 244; 1-4; 25-51
Anandanadesan, A., Chaplain, M.A.J., Karley, A.J., Hubbard, S.F. & Schofield, P.G. (2011) Mathematical modelling of the spatio-temporal dynamics of aphid-parasitoid-plant-virus interactions. In, Iannetta, P., Hubbard, S.F., Karley, A.J., Smith, B. Squire, G., & Watson, C. (2011) Agricultural Ecology Research: Its role in delivering sustainable farm systems. Aspects of Applied Biology 109; 107-113.
Cook N, Aziz N, Hedley PE, Morris J, Milne L, Karley AJ, Hubbard SF and Russell JR (2011) Transcriptome sequencing of an ecologically important graminivorous sawfly: a resource for marker development. Conservation Genetics Resources 3, 789-795.
Clarke, H.V., Barclay, A. & Hubbard, S.F. (2011) Trinidad survey shows higher survival rates for tropical birds Biodiversity Science (4)
Brown, L.K., George, T.S., Thompson, J.A., Wright, G., Lyon, J., Dupuy, L. Hubbard, S.F. & White, P.J. (2012) What are the implications of variation in root hair length on tolerance to phosphorous deficiency in combination with water stress in barley (Hordeum vulgare)? Annals of Botany 110(2), 319-328
Clark, E.L., Daniell T.J., Wishart, J.C., Hubbard, S.F. and Karley, A.J. (2012) How conserved are the bacterial communities associated with aphids? A detailed assessment of the cabbage aphid Brevicoryne brassicae (Hemiptera: Aphididae) using 16S rDNA. Environmental Entomology 41(6): 1386-1397
Brown,L.K., George,T.S., Barrett, G.E., Hubbard, S.F. & White, P.J. (2013). Interactions between root hair length and arbuscular mycorrhizal colonisation in phosphorus deficient barley (Hordeum vulgare) Plant and Soil (in press)