How I managed to miss the Common Spotted Orchid rosette in the back garden for so long beggars me. I have been religiously keeping an eye on the Bee-orchid (Ophrys apifera) rosettes five of which were showing over the late winter, but all of whom failed to throw up a flower spike this year.
However, I did manage to overlook it, that is until the 18th of May, by which time it was quite a substantial plant – growing within a foot of the patio, and only three feet away from the garden bench. We went west for a fortnight, and when we got back it was coming into flower.
My understanding is that this specie takes three to four years from seed set to a flowering plant, and only if the right mycorrhizal fungi are present in the soil. If this plant sets seed, I will be sprinkling a little of its “fairy dust” around the rest of the back garden, in the hope of developing a new colony. Some seed may also find its way to the front lawn.
Bee hotels provide me with endless enchantment – from the first hatchings of the new bees in spring, to the constant hum and movement of the adults as they prepare their nest tubes and lay down the next generation.
I have several types of bee hotel, lying along the length of a low brick wall. Two of the shop bought variety, filled with bamboo cane, which have steadily disintegrated with constant weathering. A solid wood, “bee-hive” with removable shelves, and a set of three short birch logs, whose ends I drilled.
I was unsure how the birch logs would fare, having put them out for the first time this year. They were occupied almost immediately by nest hungry Osmia bicornis.
Part way through May, O. bicornis numbers were building up and all the hotels were being utilised. I also noticed a handful of small flies, on and around the brick wall, sitting on the edges of the bee hotels, and flying in and out of the bamboo tubes.
I posted some images of the fly on the UK Diptera Facebook Group, asking for an identification.
Cacoxenis indagatar
It did not take long before the fly was confirmed as Cacoxenus indagatar. This species is a cleptoparasite of mason bees. It lays its eggs in the nest cells of the host, and when its larvae hatch, they feed on the pollen laid down by the mason bee. As a result, the bee larvae might starve to death – or even get eaten by the fly larvae, should numbers or size of pollen store dictate.
To escape the cell walls of the O. bicornis the adult fly, has a neat trick. It can inflate its head, to force a breach in the wall, a feat it may have to undertake several times to escape along the length of a nest tube. Hence it earns its vernacular as The Houdini Fly!
New Scientist [Online] has a video of the great escape artist in action:
