Many of the world's most important crop-producing countries will be fully saturated with pests by the middle of the century if current trends continue, a study has found.
More than one-in-10 pest types can already be found in around half the countries that grow their host crops.
And if this spread advances at its current rate, scientists fear a significant proportion of global crop-producing countries will be overwhelmed by pests within the next 30 years.
The research from the University of Exeter was published in the journal Global Ecology and Biogeography.
It describes the patterns and trends in the spread of crop pests, using global databases to investigate the factors that influence the number of countries reached by pests and the number of pests in each country.
Crop pests include fungi, bacteria, viruses, insects, nematodes, viroids and oomycetes.
"If crop pests continue to spread at current rates, many of the world's biggest crop-producing nations will be inundated by the middle of the century, posing a grave threat to global food security," said Dr Dan Bebber of the Biosciences department at the University of Exeter.
The study identifies the pests likely to be the most invasive in coming years, which includes three species of tropical root knot nematode whose larvae infect the roots of thousands of different plant species.
Another, Blumeria graminis, is a fungus that causes powdery mildew on wheat and other cereals.
And the Citrus tristeza virus (given its name meaning "sadness" in Portuguese and Spanish by farmers in the 1930s) is also a threat, having reached 105 of 145 countries growing citrus by the year 2000.
Fungi lead the worldwide invasion of crops and are the most widely dispersed group, despite having the narrowest range of hosts.
The study looked at the current distributions of 1901 crop pests and pathogens and historical observations of a further 424 species.
Significant use was made of historical CABI (Centre for Agriculture and Biosciences International) records, which document crop pests and diseases around the world from 1822 to the present day.
"By unlocking the potential to understand the distribution of crop pests and diseases, we're moving one step closer to protecting our ability to feed a growing global population," said Dr Timothy Holmes, head of technical solutions at CABI's Plantwise Knowledge Bank.
"The hope is to turn data into positive action."
- Daily Mail