My first encounter with solitary bees was watching a male wool carder bee Anthidium manicatum around the lavender patch by our front doorstep in 2006. The following year I planted out some lambs ear Stachys lanata in the garden hoping to attract them again but in a series of poor summers none appeared. Then in 2014 another appeared around a patch of woundwort so I planted out more lambs ear and this time had great success.
These bees are named after the nesting behaviour of the females. They rasp off hairs from plants such as woundworts and mulleins and use these to make ‘woolly sleeping bags’ for their nest cells in crevices. In July 2015 I was able to watch them at work for the first time but didn’t have any time to sketch them.
This year I made a special effort to watch them. The first appeared on some purple toadflax on 21 June but the weather was generally cool so there was little activity from the bees. I did however often find them roosting in the glass tubes of my bee hotels. It was not until mid-July that I saw much more activity. On 17 July a female was collecting ‘wool’ from the lambs ear and flying across the road where it may have been nesting under a roof slate or in a wall – I have yet to find out where but they also flew in this direction the previous year so may have a regular nesting site there.
Up to 3 females could then be seen collecting nest material. It was possible to hear them rasping away the hairs from a few metres away. They seemed very fussy about where they collected often moving about the plants several times before a large enough ball was formed. Then the bee would curl her abdomen forward clutching the woollen ball and fly off to her nest returning every five minutes or so to collect another load. See video here.
One of the females was still roosting in the glass tubes at the end of July so I marked and released her by our front door. She immediately flew to a patch of purple toadflax at the end of the garden and here I found a male. Unusually amongst solitary bees the males are much larger than the females. They defend a patch of flowers against any other bees ranging from large bumblebees to tiny Lasioglossum bees. They may also produce pheromone scents as there are several patches of purple toadflax around our garden but most of the activity was around this one. I marked ten females visiting this spot in early August and there were two other males which came by occasionally.
The dominant male mated frequently with the females. He would hover around before pouncing on her and mating for about 10 seconds. See video here. Rival males were soon chased off. I spent a few afternoons sat in the garden watching and sketching these fascinating bees. Numbers of females gradually dropped and their season came to an end with the last sighting of the male and two females on 12 August. I would love to see their nests and have tried attracting them to my bee hotels but with no luck so far, hopefully they will return next year so I can have another go.