File:Lasioglossum albipes, m, back, france 2014-06-04-11.07 (39756784195).jpg

Lasioglossum albipes, Polysocial Hairy-tongued Bee, specimen collected in France

Because of the very well known biology of Honey Bees some may believe that all bees have complex social lives. However, very few of the more than 20,000 species of bees discovered actually has a complex social life. Indeed, most bees are solitary and even most social bees live in colonies of no more than 10 individuals. The Polysocial Hairy-tongue varies in its preferences: in some parts of its range it is social, with small colonies, while in others it is entirely solitary. But why?

Generally, social bees produce two or more broods per year – minimally, the queen will produce a brood of workers and then the workers forage and construct pollen balls for the queen to lay eggs upon. If there are only two broods per year, the second one will be of males and the next year’s queens. This works well in parts of the world where the summers are reasonably long. However, in cold mountaintops, or unpredictable but cold far northern environments, the summer is too short for there to be time to produce two broods and some bees have managed to revert to a solitary lifestyle to persist in these colder areas. The Polysocial Hairy-tongue is one such species. Even within the country of France, this bee will be social in lowland areas with quite long summers, but they are solitary in mountainous regions.