About ten to 16 per cent of global crop production is currently lost to pests including fungi, bacteria, viruses, insects and nematodes. The spread of these pests is caused by a combination of human activities and natural processes, with international freight transportation thought to be a major factor. However, the new study suggests that the warming climate is allowing pests to become established in previously unsuitable regions.
A team led by Dan Bebber of the University of Exeter analysed published observations of the distributions of 612 crop pests collected over the past 50 years. They found that on average, the pests were moving polewards at a rate of 2.7 kilometres per year, although there was significant variation in the trends among the different taxonomic groups. The movement into new, previously un-colonised regions corresponded with increased temperatures during that period.
‘If crop pests continue to march polewards as the Earth warms, the combined effects of a growing world population and the increased loss of crops to pests will pose a serious threat to global food security,’ Bebber said.
This story was published in the October 2013 edition of Geographical Magazine