Oh dear, that cold must have been worse than I realised, as I see that I have missed two days! I was thinking that this is the worst cold I've had in a long time. Then I remembered that I had a bad one last spring, when what is normally the worst single day, actually lasted nearly a week. If I hadn't written that down, I would have forgotten completely. It's amazing how the body and mind forgets pain and discomfort once it has gone - until there is some threat of the the same circumstance again.
So, today back to work, despite some coughing and spluttering still. A morning in the bat loft with a plumber, followed by a butterfly transect in lovely spring weather in the afternoon. Not many butterflies about, though - those that overwintered as adults have probably had enough good weather to lay their eggs before dying off, and now we are looking at freshly emerged adults. So all I counted were a couple of speckled woods and a few orange tips.
One insect that was out in reasonably numbers was the Bee fly, Bombylius major. It's fairly easy to identify as it looks like a bee hovering at a flower, but then you realise it is actually a fly (those big eyes, plus it has only one pair of wings), with its proboscis permanently extended. Sometimes they stop to rest on bare soil or stones, as in the picture.
Bombylius major is a parasite, and has several host species, including beetle larvae and the brood of solitary wasps and bees, particularly mining bees such as Andrena. By mimicing bees, they are able to get close to the real bees' burrows. Then the female will flick her eggs into or near the nests of the host insects. The larvae feed on the food stored for the bee grubs, as well as on the young solitary bees or wasps.
Although Bombylius major is an excellent pollinator for early flowers such as primroses, the larvae limit the population of other pollinators. Fortunately the adults are only around from April to June, so host species with multiple broods per season, and those that only nest late in the summer, are not badly affected.