Different bees, different needs Part 2
Some bees have a special connection with certain flowers. These bees are called oligolectic and it means that you will see the females gather pollen only on a few species of plants. A bee species which is said to be oligolectic and associated with the bell flowers is Chelostoma, of which there are 2 natives in the UK and 4 in the Netherlands. By planting campanula, both garden varieties as well as native plants, you can attract this very small bee. They are easily overlooked as they are tiny, only 6-7 mm. If you have a bee hotel with holes ranging from 2-4mm they may even start to breed in your garden. Well worth the try!
Below a photograph of Chelostoma rapunculi which is called in Dutch the large campanula bee. It is a species not native to the UK nor Ireland (yet). Females gather pollen on campanula flowers to feed their young.
Here you can see the scopa of a female: you can clearly see the abdominal hairs where she gathers her pollen:
Another group of bees which I personally like a lot are the leafcutter bees. These have broad bodies and can be found on a variety of flowers but they seem to like members of the pea family in particular. In my garden, I hope to encourage them by growing several wild flowers such as Flat Peas, Tuberous pea (wonderful scent too!) Meadow vetchling and Spiny Restharrow and Bird’s foot trefoil. This is the first year that I am growing these plants so we have to wait and see. The female uses pieces of roses and birch for the cell walls. If you have roses and you see perfectly shaped cuts, then it is probably a leafcutter mum taking care of her offspring. Here a photograph of tuberous pea in flower, Lathyrus tuberosus
Below a picture of Megachile willughbiella and this is a male which you can see as with a bit of imagination, it looks as if the male is wearing boxing gloves.
White bryony is a plant which grows in the wild and there are female and male plants. The female flowers are very small but the male ones much showier. Bumblebees and honeybees like this plant a lot and there is one bee called Andrena florae which only gathers pollen on this plant. If the plant disappears, the bee will disappear as well. It is called a Monolectic bee as it only gathers pollen on this plant, nothing else. It is restricted to the very south-eastern part of the UK and mostly Southern Netherlands.
Here a honey bee feeding on white bryony male flowers which are a lot bigger in size compared to the female flowers.
A plant hated by so many farmers but very important to solitary bees is ragwort. This plant is a favourite food plant for the rare Heriades truncorum, another small bee. You will see this plant on yellow-flowered species of the Aster family. In my garden it is often seen on corn marigold. These bees can be encouraged to breed by putting up a bee hotel and small holes 3-4mm. It is another oligolectic bee. As you can see this is a small bee but lovely to have. It is expanding its range in the Netherlands and probably the UK too.