(NaturalNews) The world's crops are being placed at increasing risk due to declines in populations of wild pollinators, and the problem cannot be solved merely by increased reliance on honeybees, according to a study conducted by an international research team and published in the journal Science
"Our study demonstrates that production of many fruit and seed crops ... is limited because their flowers are not adequately pollinated," said researcher Lawrence Harder of the University of Calgary
. "We also show that adding more honey bees often does not fix this problem, but that increased service by wild insects would help."
The team consisted of 50 researchers who analyzed data from 41 separate crop systems in 600 fields spread across 20 countries. Crops analyzed included fruits, seeds, nuts and coffee.
Approximately three-quarters of all human foods depend at least partially upon animals such as insects, birds and bats for pollination. Although domestic honeybees are used to pollinate many crops, the majority of plans to do better with (and may ultimately be dependent on) wild pollinators that live in natural or semi-natural habitats. These habitats, often found at the edges of forests or grasslands, are increasingly being lost, and pollinator populations are falling accordingly.
No replacement for wild insects
The researchers found that fruit production was significantly lower on plants that received fewer visits from wild insects, regardless of whether honeybees
were used to pollinate them or not.
An example of wild pollinators' importance can be seen in the case of low-bush blueberry farms in Eastern Canada, researcher Steven Javorek of Agriculture Canada said. Wild bees, which evolved to pollinate the blueberry bushes, will visit the plants in any kind of weather.
"They fly on those kind of wet, cool spring days when the crop
is blooming, whereas honey bees are still tucked in their hives," Javorek said. This explains why fields with healthier wild bee populations produce so much better in years with poor weather.
Another reason that wild pollinators
outperform honeybees, Harder said, is that wild insects are more likely to visit a larger number of plants, whereas honeybees will visit many flowers on just a single plant. This means that plants visited by wild insects have higher genetic diversity, are healthier, and produce better products.
Alarmingly, populations of wild pollinators have been plunging worldwide.
"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," Harder said. "Our study highlights the benefits of considering this paradox in designing and implementing agricultural systems."
Although massive agricultural fields may seem to provide food
for pollinators, Harder notes that they do so only at certain times of year. In contrast, wild habitat provides the food that wildlife need year-round.
Measures to stem pollinator loss could include decreased use of insecticides, conservation and restoration of natural and semi-natural habitats in agricultural regions, and promoting varied land use that incorporates food and nesting resources for wild pollinators.Sources:http://www.sciencedaily.com/releases/2013/02/130228155622.htmhttp://o.canada.com