The number of different pests plaguing crops in the developing world may be vastly underestimated, contributing to severely reduced harvests in some of the world’s most important food-producing nations, say researchers.
About 200 pests and pathogens per country fly under the radar of researchers and policymakers in the developing world due to a lack of technical capacity to detect them, according to a study.
“Highly-productive countries such as Brazil, China, India, Indonesia and the Philippines are likely to be harbouring hundreds more crop pests than currently known,” says the study published in New Phytologist last month (11 February).
The team used a statistical model to relate the known distribution of about 2,000 crop destroying-organisms in 195 countries to physical and socio-economic factors, such as agricultural production, climate, and research and development (R&D) expenditure.
The researchers used the model to estimate how many pests would be found if all countries had the same GDP (gross domestic product) and R&D spending as the United States. The difference between this and the known pest numbers indicated how many pests may be going undetected: around 205 per country on average.
For example, Myanmar, which produces large amounts of rice but spends little on R&D, has reported 359 pests. The model found it may have as many as 723 pests, which may mean that only about half of the total pest burden is being detected.
“To tackle pests and pathogens we need to know they are there. Our paper suggests that more investment is needed in developing countries to help identify pests,” lead author Daniel Bebber, from Exeter University, United Kingdom, tells SciDev.Net.
This is especially true for microorganisms, which require greater technological capacity to identify them than larger pests such as insects, say the researchers.
Jan Breithaupt, an agricultural officer for the UN Food and Agricultural Organization’s division of Pest and Pesticide Management, says the study underlines the importance of facilities and expert knowledge “to prevent crop damage and manage pests proactively, particularly in developing countries”.
He says local farmers’ knowledge of their own environment — rarely taken into account in pest detection studies — should be used too.
He also warns that climate change will likely compound the problem as it will increase the number of pests affecting crops.
Francisco Morales, based at the International Center for Tropical Agriculture in Colombia, agrees that in Latin America more investment in research would increase capacity to detect and identify pests.
But he points out the need for tougher quarantine measures for imported agricultural products, too.