Bees have a much greater economic value than is widely known, according to a scientific probe into strawberry-growing published on Wednesday.

Strawberries pollinated by bees were of far higher commercial value than fruit that was self-pollinated or pollinated by the wind.

They were heavier, firmer and redder and had a longer shelf life, researchers in Germany found.

Bees are under threat from hive "collapse", a disorder that some have linked to pesticides and pollution.

According to a 2011 report by the UN Environment Programme (UNEP), pollination by bees and other insects contributed about 153 billion euros ($204 billion), or 9.5 percent, of the total global value of food production.

(Source: AFP)