Agricultural pests - viruses, bacteria, fungi, blights, mildews, rusts, beetles, nematodes, flies, mites, spiders and caterpillars - are spreading thanks to trade, travel and global warming, writes Tim Radford. The world faces a dire future of increased crop losses and growing insecurity.
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Coming soon to a farm near you: just about every possible type of pest that could take advantage of the ripening harvest in the nearby fields.
By 2050, according to new research in the journal Global Ecology and Biogeography, those opportunistic viruses, bacteria, fungi, blights, mildews, rusts, beetles, nematodes, flies, mites, spiders and caterpillars that farmers call pests will have saturated the world.
Wherever they can make a living, they will. None of this bodes well for food security in a world of nine billion people and increasingly rapid climate change.
Dan Bebber of the University of Exeter, UK, and colleagues decided to look at the state of pest populations worldwide.
They combed the literature to check the present status of 1,901 pests and pathogens and examined historical records of another 424 species. This research included the records made since 1822 by the agricultural development organization CABI.
Crop pests often emerge in one location, evolve and spread. That notorious potato pest the Colorado beetle, for instance, was first identified in the Rocky Mountains of the US in 1824.
On current trends, all pests will be everywhere by 2050
The scientists reasoned that climate change and international traffic made transmission of pests across oceans and other natural barriers increasingly probable, and tried to arrive at a rate of spread.
They found that more than one in 10 of all pest types can already be found in half of the countries that grow the host plants on which these pests depend. Most countries reported around one fifth of the pests that could theoretically make their home there.
Australia, China, France, India, Italy, the UK and the USA already had more than half of all the pests that could flourish in those countries. The pests that attack those tropical staples yams and cassava can be found in one third of the countries that grow those crops.
Continue reading at ENN affiliate The Ecologist.
Insect image via Shutterstock.