Photo: Pixabay/SanchitaSarker
Insects worldwide are facing a variety of environmental stresses, which have led to precipitous declines in their numbers. That poses threats not only to the insects themselves but to biodiversity and food security too.
One of those threats lies in a growing absence of pollinators, which is impacting agriculture. In the tropics pollinator-dependent staples such as coffee, cocoa, watermelon and mango may be most at risk, according to a team of scientists at University College London and the Natural History Museum in the United Kingdom.
The researchers examined more than 1,500 crop-growing sites worldwide and catalogued over 3,000 insect pollinator species. They have found that pressures from climate change and agricultural activities have “led to substantial declines in both the abundance and richness of insect pollinators.”
That is disconcerting because three-quarters of crops depend on pollination by animals to some extent. A model created by the researchers indicates that pollination-dependent crops most at threat in coming decades include several important staples produced widely in the tropics and consumed worldwide.
“Our research indicates that the tropics are likely most at risk when it comes to crop production from pollinator losses, primarily due to the interaction of climate change and land use. While localised risks are highest in regions like sub-Saharan Africa, northern South America, and Southeast Asia, the implications of this extend globally via the trade in pollination dependent crops,” explains Joe Millard, one of the researchers behind the study.
Coffee, cocoa, mango and watermelon all rely on insect pollination and so are at the greatest risk from a loss of insects along with other threats such as climate change, which is leading to prolonged droughts.”These crops play vital roles in both local economies and global trade and their reduction could cause increased income insecurity for millions of small-scale farmers in these regions,” the scientists stress.
“As insects decline, due to being unable to cope with the interacting effects of climate change and land use, so too will the crops that rely on them as pollinators. In some cases, these crops could be pollinated by hand but this would require more labour and more cost,” Millard says.
