Findings of a new study have showed that only 2% of wild bee species contributed 80% of pollination around the world. The study was published on Tuesday in the journal Nature Communications. It provided insight into how few species actually do all the work, said Mace Vaughan, co-director of the Pollinator Program at the Xerces Society.

David Kleijn, an ecologist at Wageningen University in the Netherlands, has to say that the 80-20 rule seem to exist for work with wild species. He said, “Different crops, different countries and climatic regions, 1,500 kilometers apart, and yet the bees pollinating these crops were mostly the same”.

He observed this while studying the insects in farm fields in the Netherlands and in Southern Italy five years ago. Commercial bees, Apis mellifera, do about half the pollination work witnessed by researchers.

Kleijn said they found that crop pollination was the focus of fewer than eight wild bee species. Wild plants were used for foraging by all the other types of wild bees.

The common Eastern bumblebee (Bombus impatiens) was found making the greatest contribution to crops. On average, its pollination services accounted for $390 per acre.

Researchers said more than 20,000 wild bee species exist worldwide. Many of them are rare and threatened. Kleijn’s research team has suggested farmer to plant hedgerows of wildflowers and keep strips of wild grass around the edges of their fields to more than triple the likelihood of wild bees to pollinate their crops. Kleijn said wild bees have intrinsic value.