Many readers will be aware of leaf-cutter ants from wildlife documentaries, but I would guess that fewer are aware that in the UK we have leaf-cutter bees. These bees cut out small sections of leaf then fly back to their nests with them, including 'bee hotels' that can be bought or made for use in gardens.
Since the release of Steven Falks field guide to bees (and more recently Nick Owen's Bees of Norfolk) I have been trying to identify more species of bee. My bee list is currently 39, which might not seem too bad if it wasn't for the fact that in west Norwich friends Vanna and Jeremy Bartlett have recorded 49 in their garden alone! I have also had lots of help with identification and verification of my records. Many species of bee can look very similar to each other, so it is always nice to find a genus or species that is quite distinctive. Identifying leaf-cutter bees to species can be tricky, but identifying them as a group isn't too bad. They are found in a range of habitats, including gardens, so you may well have come across them without realising. Below are some photos and points to help you identify them.
Typically leaf-cutter bees have a chocolate brown thorax (the round body segment between the head and abdomen), a dark brown, flattened-looking abdominal segments and pale furry edges (photo 1). They often strike a distinctive posture with the abdomen pointing upwards (photo 2), and the females have a 'pollen brush' underneath. This is quite distinctive as a mass of orangey hairs, and this replaces the pollen brushes that most species have on their legs to carry pollen. Some species have all orange hairs, whilst others are orange but then darker towards the end (photo 3)
If you're interested, the first two photos show Megachile centuncularis at the edge of a path near my house in Norwich, whilst the last photo is Megachile ligniesca from Alderfen Broad. Note the dark hairs under the end of the bottom bee, and the lack of hairiness on most of the last tergite (abdomen segment). So there we go, a few ID tips there. As for Andrenas? Lump 'em all as "Mining Bee" I say.