- In the first study of its kind, scientists looked at 1,300 insect and fungal pathogens, and found that almost a third of the 124 countries included in the study have a high risk of being invaded by at least one of the pathogens.
- China and the United States are the top two potential source countries for the pests, according to the study.
- Big agricultural producers like China, the U.S., India and Brazil would suffer the greatest monetary losses from invasive crop pests, the study found. But developing countries located in sub-Saharan Africa are the most vulnerable to these pests in terms of relative cost.
Exotic species can wreak havoc on a country’s ecosystem and economy. The extensive damage that invasive species cause to crops and forests in the United States alone, for example, is estimated to be around $40 billion each year.
But the threat from invasive insects and pathogens is not equally damaging for all countries. Some are at more risk than others, concludes a new study published in the Proceedings of the National Academy of Sciences of the U.S.A.
In the first study of its kind, scientists looked at 1,300 insect and fungal pathogens, and found that almost a third of the 124 countries included in the study have a high risk of being invaded by at least one of the pathogens.
“This is the first analysis summarizing the invasive species threat to global crop production on a country- by-country basis,” the authors write in the paper.
To estimate each of the 124 country’s vulnerability to invasive species, the team assessed the chance of an invasive species entering, establishing and damaging crops in a country. They used data on the global distribution of invasive species, trade levels of each country, the direction of trade between countries, the types and values of crops grown in each country, and the Gross Domestic Product (GDP) of each country to find these likelihoods.
The data revealed that China and the United States are the top two potential source countries for the pests.
“China and the U.S. have very active trading relationships with many countries worldwide and these provide potential links for transport of pest and disease organisms to novel areas,” Matthew Thomas, professor and Huck Scholar in Ecological Entomology and a researcher in the Center for Infectious Disease Dynamics, Penn State, said in a statement.
The study’s models also estimated that big agricultural producers like China, the U.S., India and Brazil would suffer the greatest monetary losses from invasive crop pests. In terms of relative cost however, sub-Saharan African countries, such as Malawi, Burundi, Guinea, Mozambique, and Ethiopia, are the most vulnerable to these pests, the study found.
“These countries generally do not have diverse economies making them disproportionately more dependent on agriculture,” Dean Paini, senior research scientist, Commonwealth Scientific and Industrial Research Organization and Plant Biosecurity Cooperative Research Centre, said. “As a result any threat from invasive species can potentially have a greater relative impact on these countries.”
Invasive species will continue to remain a major threat around the world. And this study is the first step towards the management of invasive species at the global scale, Paini added.
“By identifying the countries and regions that are most vulnerable, governments can make informed decisions regarding the deployment of resources necessary to protect their borders and agriculture industries by limiting the further spread of invasive species,” he said.
- Paini DR et al (2016) Global threat to agriculture from invasive species. doi: 10.1073/pnas.1602205113. PNAS. June 20, 2016