These solitary bees emerge quite late in the year as full adults and only live a few weeks. The males can be seen in August and the females follow in September.
They are the latest foragers to emerge, and they do well in colder weather. Many other species of bees are already gone by then, so they have less competition for their favorite flowers. They fly and forage until early November, so they have a very short season.
They are specialist bees, foraging mostly on pollen and nectar from ivy flowers, although when ivy is scarce, they will visit other plants such as specific daisy flowers. Larval brood cells are stocked with ivy nectar and pollen almost exclusively by the female ivy bee. The grubs pupate and remain safe underground until autumn.
On average, the female is 13 mm or (0.50 inch). Males are slightly smaller, at 10 mm long (0.39 inch). They have hairy orange-brown ginger thoraxes and defined stripes. They look like honeybees.
Unfortunately, western European ivy bees are often parasitized by the meloid beetle larvae, and these eat the nectar and pollen supplies left by the female ivy bees for their young.
Males can be highly competitive when it comes to mating, and several can try to mate with a single female, which can often look like a frenzied ‘mating ball.’
This 2:42-minute video by George Pilkington takes us into the world of ivy bees:
Tens of thousands of them can be found at times in highly concentrated nesting locations in clay and sandy soil, and they particularly like soft rock cliffs and hills.
The species Colletes hederae is not found in North America. They are spread over most of the European continent, and are known to live in Austria, Belgium, Channel Islands, Croatia, Cyprus, southern England, France, Germany, Greece, Italy, and many other European countries.
They were first observed in the UK in 2001 in Dorset, where they came over from the European continent.
These bees have been confused with other mining bees in the past and only recently have come to be recognized as a distinct species on their own.
The Colletidae family of bees, to which the ivy bees belong, are also known as plasterer or polyester bees, because they smooth the walls of their nests with their mouth secretions. These look like cellophane when dry. In the Colletes family there are five sub-families, 54 genera, and over 2,000 species, and they are all solitary.