It had been one of the first really hot days of the year; also the day Andy Murray won the men’s title at Wimbledon. We had been to the coast: for the sea and for a picnic in the early evening sun. When we got back and had unpacked the car, I went in to our garden. We have a Wisteria growing as a small tree in a pot. It had its two weeks of floral glory in May but its copious foliage now demands regular watering especially during hot weather.
While I was giving it a drink, I heard a strong buzzing near my head. Sure enough there was a blackish bee to my right, perched on one of the leaves. As I watched, it deftly cut through the leaf and rose up carrying a leaf fragment between its legs before flying away, rather like a Harrier Jump Jet. I had no camera to record this astonishing (to me) event which was a pity. When I had a look in my book of Small Woodland Creatures, I realised that this was a Leafcutter Bee, one of the UK’s solitary bees and an important pollinator for summer flowers, vegetables and herbs.
Next morning I had another look at the Wisteria, secretly hoping for a rerun of the events of the previous day. I didn’t see any more Leafcutters but, based on their characteristic calling card, it was clear they had been here before on more than one occasion. There were several circular holes (~ 1cm) in the leaves, the trademark of the Leafcutter Bee. When I had watched the bee, the fragment of leaf appeared about the same width as the bee and a little longer, but I believe this is because the bee folds the circle of leaf in to an aerodynamic form.
The Wisteria seems quite happy despite the invasion of the Leafcutters and anyway the leaf fragments are very important for the life cycle of these creatures so we must let them get on with it. Mated females work hard all summer to provide next year’s brood. She makes her nest in holes in plant stems, dead wood, cliffs and old walls. Leafcutters also seem happy to take up residence in purpose built bug houses, but more about that later. The female Leafcutter lines the nest with pieces of leaf and petals and constructs brood cells in the tube, providing each cell with pollen and nectar and laying one egg. She seals the cell with a piece of leaf and then starts on the next cell continuing along the tube until it is nearly full. She then collects many pieces of leaf and puts them at the nest entrance cementing them together to form a solid barrier to protect against all sorts of threats. The young bees develop in the individual cells where they overwinter and emerge the following June and the cycle starts again. There are some lovely pictures and drawings of Leafcutters on this web site.
By chance, I also visited the local community garden (The Leechwell Garden) that day. The garden has many bee-friendly plants and one of the people who works there showed me their bug house. In one of the tubes was the nest of a Leafcutter bee complete with the neat sealing of leaf pieces. Here is a photo showing the (out of focus) sealed nest tube and the green leaves. I make no linkage between the Leafcutter in my garden and this nest but it is a nice coincidence.