Wild bees make honey bees busier

© SARAH GREENLEAF

Sarah Greenleaf, while a graduate student at Princeton University, led a study that showed wild bees help honey bees become more effective pollinators in central California farms where 90% of US hybrid sunflower seeds are produced. ¹

It's "a fascinating example of how species interactions enhance a vital ecosystem service," comments Valerie Eviner at the University of California, Davis, on the Faculty of 1000 Web site.

According to Greenleaf's report, there are two reasons that wild bees may cause honey bees to move from flower-to-flower and pollinate more frequently. Her team observed that male wild bees latch onto potential female honey bee mates, who generally flew away immediately. Secondly, female wild bees with pollen loads were seen flying into honey bees, causing them to move and sometimes alter their patterns.

"This paper demonstrates that honey bee pollination of a crop doubles when wild bees are present in an agricultural landscape. The impact of wild bees on honey bee pollination was five-fold higher than the direct pollination provided by the honey bees [from an average of 3 seeds per visit to 15 seeds]. [It's] a compelling example of how landscape-scale conservation can benefit agriculture," writes Eviner.