A new map showing bee species around the world is the most comprehensive of its kind ever compiled.
There are over 20,000 species of bees, but until now information about how these are spread around the globe has been hard to come by.
Researchers created the map by combining the most complete global checklist of known bee species with almost 6 million additional public records of where individual bee species have appeared around the world.
The analysis was published in the journal Current Biology this week.
Researchers found there are more species of bees in the Northern Hemisphere than the Southern, and more in arid and temperature environments than in the tropics.
"People think of bees as just honey bees, bumble bees, and maybe a few others, but there are more species of bees than of birds and mammals combined," says senior author John Ascher, an assistant professor of biological sciences at the National University of Singapore.
"The United States has by far the most species of bees, but there are also vast areas of the African continent and the Middle East which have high levels of undiscovered diversity, more than in tropical areas."
Ascher said the relative abundance of bee populations in temperate regions goes against the pattern of nature that sees most plants and animals increase in diversity towards the tropics and decrease towards the poles.
He said the research was an "important first step" in assessing potential declines of bee populations around the world.
"We're extremely interested in abundance of bees, but that's something that has to be done in relation to a baseline," said Ascher.
"We're trying to establish that baseline. We really can't interpret abundance until we understand species richness and geographic patterns."
The research team is hopeful their work will help global conservation efforts.
"Many crops, especially in developing countries, rely on native bee species, not honey bees,' said fellow author Alice Hughes, an associate professor of conservation biology at Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences.
"There isn't nearly enough data out there about them, and providing a sensible baseline and analysing it in a sensible way is essential if we're going to maintain both biodiversity and also the services these species provide in the future."
