Bees not be-all and end-all in crop pollination

By AAP with AG Staff December 1, 2015
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Insects such as flies and wasps can offer insurance against the worrying decline in honeybee populations, according to new research.

BEES ARE DECLINING worldwide, but other insects may be just as important for pollinating certain major crops, and could be more resilient to environmental changes, according to new research.

In a recent study led by Australian scientists, researchers found that flies, butterflies, moths, beetles, wasps, ants and thrips provide, on average, 39 per cent of visits to crop flowers, while crops such as mangoes, custard apples, kiwifruit, coffee and canola depend on non-bee pollinators.

Therefore, farmers who use pesticides that spare bees but kill other insects might be making a mistake, the researchers argued.

Reliance on bees a risky strategy

“The global reliance on honeybees for pollination is a risky strategy given the threats to the health of managed honeybee populations due to pests and diseases such as Varroa mites and colony collapse disorder,” said co-author Margie Mayfield, a plant ecologist at the University of Queensland.

“Non-bee insects are an insurance against bee population declines,” she added.

Until now, little research has focused on the role of non-bee pollinators in agriculture, but lead author Romina Rader from the University of New England, Armidale, said the team discovered that non-bee pollinators were crucial to the ecosystem, performing anywhere from 25 to 50 per cent of the total number of flower visits.

“Although non-bees were less effective pollinators than bees per flower visit, they provided slightly more visits,” Rader said. “These two factors compensated for each other, resulting in pollination services similar to bees.”

Non-bee pollinators were also found to be less sensitive to habitat fragmentation than bees, offering even more reason to protect them.

The findings were published in the US peer-reviewed journal Proceedings of the National Academy of Sciences.