Falling numbers of wild bees and other pollinating insects
are hurting global agriculture, a study released on Thursday found.
Managed populations of pollinators are less effective at
fertilising plants than wild ones, the researchers said, so the dearth of
pollinating insects cannot be solved by simply introducing others.
"Adding more honey bees often does not fix this
problem, but... increased service by wild insects would help," said
Lawrence Harder, a scientist with the University of Calgary in Canada, which
led the study.
Pollinating insects usually live in natural or semi-natural
habitats, such as the edges of forests, hedgerows or grasslands.
These habitats are gradually being lost as the land is
cultivated for agriculture, but, as a result, the abundance and diversity of
wild pollinators crucial for the crops' success is declining.
How the study was
The researchers analysed 41 crop systems around the world,
including fruits, seeds, nuts, and coffee to examine the impact of wild
pollinators on crop pollination.
"Paradoxically, most common approaches to increase
agricultural efficiency, such as cultivation of all available land and the use
of pesticides, reduce the abundance and variety of wild insects that could
increase production of these crops," says Harder.
He said tomatoes, coffee and watermelon are among the key
crops which are likely to suffer from the declining population of wild
Most flowering crops
need to receive pollen
Most flowering crops need to receive pollen before making
seeds and fruits, a process that is enhanced by insects - like bees, but also
flies, butterflies and beetles - that visit flowers.
The research, which was published in the journal Science, was carried out by an
international team of some 50 researchers, who collected data from 600 fields
in 20 countries.
The study called for new efforts to conserve and restore the
natural habitats of honey bees and wild insects.