Today's re-run of Groundhog Day was marked by the arrival of the small batch of emergency pond plants I ordered last week from Sweet Knowle Aquatics, who seem to have got their.... act.... together rather better than some of the bigger suppliers. The Leicestershire nursery where I placed a larger order a couple of weeks ago is currently managing to despatch three days worth of orders per week - a situation which in my mind is like trying to run up a downward escalator - and if we're lucky ours might just arrive some time in the second half of May.
After a cold, blowy, and wet morning, the afternoon turned dry and the sun even attempted to come out - though it was still chilly, especially when I was shoulder-deep in the wild pond, placing a Nymphoides peltata down in the centre. Because of the temperature and the wind there weren't many insects about, but I did manage to creep up on this chequered hoverfly, Melanostoma scalare, feeding on a rhubarb flower head.
Melanostoma scalare is a very common hoverfly, but easily overlooked because it's one of the small species - this female is probably about 8mm long. Interestingly, I think it's the only species I've ever seen in which the halteres are (often though not always) green, though I haven't been able to find out why this should be the case. In this photo the left haltere is the green blob just behind the base of the wing; it's a kind of balance organ, detecting rotational forces and providing feedback to the muscles controlling the wing, and thus allowing the hoverfly to adjust its position in space.
The image looks better full-screen, if you have the time to check it out.