Domesticated Bees and Wild Pollinators
It didn’t take long for people to figure out how to manage wild pollinators to increase crop yield.
In 1885, bumble bees (Bombus terrestris and B. ruderatus) were brought to New Zealand to pollinate fields of red clover. By the 1930s, farmers were paying bee keepers in Denmark to bring their bees to pollinate crops, and the practice soon spread. The manageable, social, and hard working honey bee (Apis mellifera) quickly became the dominant commercial bee pollinator, and is now often more valuable as a pollinator than a producer of honey.
In California, bees are trucked in by farmers from across the country to pollinate almond trees. The trees bloom for just a few weeks (sometimes less) from mid-February through mid-March, and there aren’t enough honey bees in the state to pollinate all of those flowers, even if they were all on the job. It’s the world’s biggest pollination event.
Most Prized Pollinator: Honey Bees Tumble from the Top
The honey bee’s position as the most important pollinator of crop plants has been challenged by recent research.
An international team reviewed data collected from 600 fields in 41 crop systems and 19 countries and found that honey bees do not, in fact, replace wild insects as crop pollinators. Flowers set more seeds when visited by wild insects, and the more plants that were visited by wild insects, the more likely they were to set fruit. In some places the researchers considered, wild insects were pollinating most of the plants despite rented honey bees being present.
Honey bee populations have been declining in recent years, in what is probably the world’s most documented instance of ill insect health. They’ve been severely impacted by Colony Collapse Disorder, invasive insect parasites, disease, and pollution, including pesticides.
So, can we relax and leave pollination to the wild insects? Sadly, another recent study showed that wild insect pollinators are also in decline. A team at Montana State University compared data on wild insects collected from the same place in the late 1800s, the 1970s, and more recently, finding that the number of wild bee species has declined precipitously: from 109 to 54. Plants are also visited less frequently (46% less), probably because bee populations have declined, but also because plants are more widely dispersed across the landscape.