Bees are flying insects closely related to wasps and ants, and are known for their role in pollination and for producing honey and beeswax. There are nearly 20,000 known species of bees though many are undescribed and the actual number is probably higher. They are found on every continent except Antarctica, in every habitat on the planet that contains insect-pollinated flowering plants. Honey bees are more effective at pollinating almonds when other species of bees are present, says an international research team in ground-breaking research just published in the Proceedings of the Royal Society. The research, which took place in California's almond orchards in Yolo, Colusa and Stanislaus counties, could prove invaluable in increasing the pollination effectiveness of honey bees, as demand for their pollination service grows. When blue orchard bees and wild bees are foraging in almonds with honey bees, the behavior of honey bees changes, resulting in more effective crop pollination, said lead author Claire Brittain. Wild bees include non-managed bees such as bumble bees, carpenter bees and sweat bees.
"These findings highlight the importance of conserving pollinators and the natural habitats they rely on," Brittain said. "Not only can they play an important direct role in crop pollination, but we also show that they can improve the pollination service of honey bees in almonds."
Bees play an important role in pollinating flowering plants, and are the major type of pollinator in ecosystems that contain flowering plants. Bees either focus on gathering nectar or on gathering pollen depending on demand, especially in social species. Bees gathering nectar may accomplish pollination, but bees that are deliberately gathering pollen are more efficient pollinators. It is estimated that one third of the human food supply depends on insect pollination, most of which is accomplished by bees, especially the domesticated European honey bee.
California's almond acreage now totals more than 800,000, and each acre requires two bee hives for pollination. Honey bee-health problems have sparked new concern over pollination services.
"In orchards with non-Apis (non-honey bees), the foraging behavior of honey bees changed and the pollination effectiveness of a single honey bee visit was greater than in orchards where non-Apis bees were absent," the researchers wrote in their abstract.
Brittain said that the field experiments "show that a diversity of pollinators can improve pollination service, through species interactions that alter the behavior and effectiveness of a dominant pollinator species."
"This is one of our first demonstrations on how to increase the efficiency of honey bee pollination through diversification of pollinators," said Williams, who joined the team in 2010. "With increasing demands for pollination-dependent crops globally, and continued challenges that limit the supply of honey bees, such strategies to increase pollination efficiency offer exciting potential for more sustainable pollination in the future."
"Almond is a $3 billion industry in California," said Kremen, who is also an affiliate with the UC Davis Department of Entomology and works closely with scientists at the Harry H. Laidlaw Jr. Honey Bee Research Facility, UC Davis. "Our study shows that native bees, through their interactions with honey bees, increase the pollination efficiency of honey bees — the principal bee managed for almond pollination — and thus the amount of fruit set."
The world produced 2.51 million tonnes of almonds in 2010 according to Food and Agriculture Organization, with United States the largest producer at 1.41 million tonnes.
Native pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis, identified the bees in the Klein-Kremen project. The species he identified for the project in 2008-09 totaled 50 species, including bumble bees, small carpenter bees, sweat bees, digger bees, mining bees and blue orchard bees.
"Now we know about bee behavior — that they move more between orchard rows when non-Apis bees are around — we need to study the reason why they move," Brittain noted. "One route we will be exploring is the chemical footprints that the bees are leaving on the flowers."
Professor Klein lectured on "Can Wild Pollinators Contribute, Augment and Complement Almond Pollination in California" at a seminar on Feb. 17, 2010, to the UC Davis Department of Entomology. Her seminar was video-recorded and can be viewed here: https://admin.na4.acrobat.com/_a841422360/p37649788/.
For further information see Bees,
Bee and Pollen image via Wikipedia.