The following shot certainly illustrates that trend as far as I'm concerned, but before I discuss it, what type of insect do you think the following picture shows? (bumblebee, wasp, fly, other?):
|Male Eristalis intricarius|
A few identification pointers might help. Firstly, it has only two wings; flies have two wings, bees have four. Secondly, the head is almost completely made up of eyes. In a bee, the eyes are long and narrow, with visible parts of the 'face' on both sides of the eyes. (Incidentally, the fact that the eyes meet in the middle is what makes it so clearly a male). Thirdly, what appears to be an orange stripe between the wings is actually the shiny scutellum, and isn't really a stripe at all. Finally, if you look carefully at the wing veins, you can clearly see the famous 'Eristalis bulge', which is unique to the Eristalis group of hoverflies:
The shot also illustrates another of the wing features which identify hoverflies: the 'False margin':
The trailing edge of the wing is not constrained by a vein: it is free to flex as the wing moves. I rather suspect this is one of the main reasons why a hoverfly can hover so accurately.
In terms of earliness, I have only once seen Eristalis intricarius before June: I have come to regard it as a summer species. The references say from March, but that would probably be a date from much further south.
The next shot shows a couple of tiny flies (on Dandelion for scale). On the left is a Sepsid fly: these run around on leaves and flowers with their wings flapping up and down in a semaphore fashion. On the right is one of our smallest hoverflies, Neoascia podagrica:
|Sepsid (L) and Neoascia podagrica (R)|
Here's a close-up of the (8mm. long, female) hoverfly:
This is again much earlier than I would normally expect to see it.
In terms of grasses, the first to flower around here is usually Sweet Vernal Grass, but that hasn't appeared yet. Instead, I found Meadow Foxtail: