Professor Keith Day
Director of the Environmental Sciences Research Institute
School of Environmental Sciences
University of Ulster, Coleraine
Northern Ireland BT52 1SA
kr.day@ulster.ac.uk

Research Interests
• Insect-plant relationships
• Population dynamics of forest insects
• Community structure and change in forest arthropods
• Effects of insect feeding on the growth dynamics of trees
• Risk assessment and economic costs of tree damage
• Management of plantation forest pests
• Population ecology and foraging of birds and mammals
• Conservation refugia for birds
My principal research interest is in the population ecology of forest insect herbivores, and reciprocal interactions with the trees on which they feed. This has included a range of studies on ten species of insects, most associated with conifers. I have a longstanding interest in the ecology of the green spruce aphid (Elatobium abietinum) and have contributed at an international level to understanding its population dynamics, its impact on trees and its responses to a variable host. I have an equally strong interest in the ecology of another forest insect, the pine weevil (Hylobius abietis), and have played a significant role in concerting the international research effort aimed at its sustainable management. A major volume on this has recently been published.
My other interests are twofold. The first of these is the use of ground beetle (Carabidae) community characteristics as indicators of forest structural change. The second is linked to work on insects through a focus on population, but includes studies of birds and mammals aimed at clarifying and solving regionally significant conservation problems. This research has addressed problems pertaining to diving ducks and grebes of Lough Neagh, breeding cormorants and chough of the north coast of Ireland, whooper swans in the vicinity of Lough Foyle, and otters in various N.I. catchments. I owe a great deal to collaboration with other scientists including eighteen doctoral research students who have received their PhDs under my supervision.

Research Student: Freia Bladon

Selected publications

2006

Day, K.R.,Docherty, M., Leather, S.R. and Kidd, N.A.C. (2006) The role of generalist insect predators and pathogens in suppressing green spruce aphid populations through direct mortality and mediation of aphid dropping behavior. Biological Control , 38: 233-246 .

2005

Williams, D.T., Straw, N.A. and Day, K.R. (2005) Performance of the green spruce aphid, Elatobium abietinum ( Walker) on previously defoliated Sitka spruce. Agricultural and Forest Entomology, 7(2): 95-105.

2004

Day, KR., Armour, H., Docherty, M. (2004) Population responses of a conifer-dwelling aphid to seasonal changes in its host. Ecological Entomology , 29 (5): 555-566.

Lieutier, F., Day, K.R., Battisti, A. Grégoire, J.-C. and Evans, H.F. (Eds.) (2004) Bark and wood boring insects in living trees in Europe, a synthesis. Kluwer Academic Publishers, Dordrecht, 569p.

2003

Armour, H., Straw, N.A. and Day, K.R. (2003) Interactions between growth, herbivory and long-term foliar dynamics of Scots pine. Trees – Structure and Function 17: 70-80.

Williams, D.T., Straw, N.A. and Day, K.R. (2003) Defoliation of Sitka spruce by the European spruce sawfly, Gilpinia hercyniae (Hartig): a retrospective analysis using the needle trace method. Agricultural and Forest Entomology 5 (4): 235-246.

2002

Evans, DM. and Day, K.R. (2002) Hunting disturbance on a large shallow lake: the effectiveness of waterfowl refuges. Ibis, 144 (1): 2-8.

Thorpe, K.V. and Day, K.R. (2002) The impact of host plant species on the larval development of the large pine weevil, Hylobius abietis L. Agricultural & Forest Entomology 4 (3): 187-194.

Straw, N.A., Armour, H.L and Day, K.R. (2002) The economic costs of defoliation of Scots pine ( Pinus sylvestris L.) by pine looper moth, ( Bupalus piniaria L.). Forestry 75(5): 525-536.

Colhoun, K. and Day, K.R. (2002) Effects of grazing on grasslands by wintering Whooper swans. Waterbirds 25 (Special Publication 1): 168-176.

2001

Evans, DM. and Day, K.R. (2001) Does shooting disturbance affect diving ducks wintering on large shallow lakes? A case study on Lough Neagh, Northern Ireland. Biological Conservation, 98(3): 315-323.

Henry, C.J. and Day, K.R. (2001) Egg allocation by Bracon hylobii Ratz., the principal parasitoid of the large pine weevil ( Hylobius abietis L.), and implications for host suppression. Agricultural and Forest Entomology, 3: 11-18.

Halldorsson, G., Docherty, M., Oddsdottir, E.S., & Day, K.R. (2001) The performance of different populations of the green spruce aphid ( Elatobium abietinum Walker) at different temperatures. Icelandic Agricultural Sciences, 14: 75-84.

Evans, D. M. & Day, K. R. (2001) Migration patterns and sex ratios of wintering diving ducks in Northern Ireland with specific reference to Lough Neagh . Ringing & Migration 20: 358-363.