61. Ditomyiidae – sun seeker

I thought I was done with fly families for the year – except for one up my sleeve which I was keeping as a finale. But a sunny afternoon drew me out from my struggles with annoying anthomyiids (bristles on legs, crucial features on hidden genitalia, awkward females, comparative adjectives without helpful figures, lots of head-scratching) for a walk through the woods. I checked out the icehouse where I bagged my first fly family on the first of January – Trichoceridae of course. There were no hibernating moths this time, but four Peacock butterflies, slivers of darkness, and one spreadeagled against the wall so as to scare me with its eye spots.

After several days of rainy deluges the river banks have been smoothed away, the vegetation toppled as if it had been scythed, the river still high and brown. As I emerged from the trees a heron lifted and croaked and floated away. This time of year the haugh is almost bare of flowers – just an odd yarrow parasol and fading bouquets of ragwort, but as if to compensate, the trees are in full colour – larch rich in yellow and russet, invisible the rest of the year but now the eye-candy across the river. At the spot on the banks where there used to be a bridge, two copper beeches were holding on to their leaves and catching the late afternoon sun. I settled myself amongst their comfortable roots and watched the river mumbling by, fidgeting in its hurry to be somewhere else. A dipper called as it whizzed upstream and in the other direction a buzzard mewed restlessly.

Ditomyia fasciata, female

There were of course no flies about, this being November, but I had brought my pooter along anyway, just in case. At the edge of my vision something flitted by and landed on the tree trunk above my head where the weak sun was warming the cold grey bark. I ended my sun saltuation and also that of the fly, the only one I saw apart from a twitchy blow fly that wouldn’t let me anywhere near it. Anispodidae, I thought, which was the third family of the year when it turned up in January in my bee shed, though the wings looked different with big dark patches – perhaps it was a different species. But under the microscope it turned out to have a different wing pattern, and it emerged from the key as Ditomyiidae, another family to have been hived off from the fungus gnats. There are only three species found in the UK, and this looked to be Ditomyia fasciata, seemingly unrecorded north of Nottingham. Nature’s way of telling me to spend quite so much time at the microscope.

1. Trichoceridae – ice house

1st January 2019 – The Year of the Fly

This is among other things, the “Year of the Fly” (http://yearofthefly.org/), and so, revisiting a boyhood interest that has now been on ice for four decades or more, I thought it would be fun to see how many of the more than 100 families of flies present in the UK I could find this year. The flies I mean are the two-winged flies that are members of the order Diptera, though just to confuse things, some have dispensed with wings altogether and cling onto the backs of bees, bats, birds and beasts.

The first of January might not seem like the best day to go looking for flies – but I knew where I would find some whatever the weather. Through the woods at the bottom of our garden is an ice-house, a left-over from the days when the surrounding area was somewhat grander with its mansion-house, stables, walled garden and, to keep things fresh since there was no refrigeration, an ice-house.

It’s a stone-built cylinder with a domed roof and a short entrance that used to have a door. In the winter ice would be brought in from the river, or possibly from specially created ponds nearby, and thereafter used as a cold store or source of ice. Nowadays, there is no ice inside, even in the depths of the winter, which makes it a good place to hibernate for herald moths (Scoliopteryx libatrix) which prefer the ceiling, leaving the walls to the spiders and multitudes of winter gnats. As soon as you poke your head and shine a light around these lift off grumpily, wary of the spiders lurking with intent, and shift along the wall a few feet.

Winter gnats are members of the family Trichoceridae, and look like miniature daddy-long-legs. They are easy enough to identify because of their distinctively short A2 vein that starts off with great intentions and then just gives up. I am hoping that this won’t be the trajectory of my Year of the fly!

Wing drawing from http://drawwing.org/insect/trichoceridae-wing