Abstracts

Climate Change and the Fate of Cereal Aphids

Jonathan Newman
University of Guelph
jnewma01@uoguelph.ca

Climate change will drive dramatic changes in the abundance and distribution of species. Assessing the impacts of climate change on our agricultural systems is essential for mitigation planning. Aphids are one of the largest and most important crop pests and disease vectors worldwide but particularly in temperate regions. Experimental evidence for climate impacts on aphids has been ambiguous, prompting some observers to conclude that aphid responses are "idiosyncratic" and not predictable a priori. I investigated aphid responses to climate change with a series of mechanistic mathematical models that combine temperate grass physiology and aphid population dynamics. Initially, I used the model to show that, although aphid responses might be varied, they are understandable and predictable in terms a few general mechanisms. I then used the climate projections from the UK's Hadley Centre for both Southern Britain and wheat growing regions of Canada, to drive the grass-aphid model. The model generally predicts lower summer abundances of cereal aphids, but there will also be a shift toward greater abundances in some areas, particularly in the northern regions. More importantly, the model emphasizes the need to experimentally consider a suite of variables not currently part of most experimental approaches.

2005-04-05