Crop-damaging insects, bacteria, fungus and viruses are moving poleward by nearly three kilometers each year, helped by global warming, a study has said.
A team at Britain’s University of Exeter trawled through two huge databases to chart the latitude and dates for the earliest record of 612 crop pests.
Since 1960, these pests have been heading either northward or southward at a rate of around 2.7km yearly.
They move into land that opens up for habitat because of higher temperature and its impact on local weather. The distance is an average figure, as some pests have travelled faster or slower than this.
Over the last half-century, global surface temperatures have risen by an average of 0.12?C per decade.
Countries at higher latitudes have more resources than economies in tropical zones in combating the problem, and regions that previously were too cold for agriculture will also open up to the plough.
Even so, the peril of advancing pests should not be underestimated, as these countries are the planet’s biggest and most productive crop growers, says the paper.
“If crop pests continue to march poleward 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,” said one of the authors, Dan Bebber.