Country diary: the thatch is buzzing with sleepy flies | Environment

The low buzz gives them away. The thatched roof I’m working on, perched on a hillside above the pigeon-grey Kingsbridge estuary in Devon, is full of insects. I have replaced the ridge; the final job is to clean down the roof. I flick away the off-cut strands of new wheat, bright yellow against the grey-brown old thatch, and “dress” the roof with the thatcher’s most important tool – a paddle-like implement that here in Devon we call a drift, though in most parts of England it’s known as a leggett.

As I slap the reed into place, clouds of flies tumble out and buzz drowsily into the winter air. Here on the hip – the part where the main face of the roof turns the corner into the triangular end – there are gaps between the stems of reed that are perfect for hibernating flies. Hymenoptera seem to prefer the densely packed wheat ridges: I found a queen hornet there last January, sprawling on a clump of moss, all yellow and ginger bristliness.

6748 - Country diary: the thatch is buzzing with sleepy flies | Environment

The jackdaw (
Corvus monedula) is often thought to damage roofs in search of nest material, but is more often in search of insects. Photograph: Nick Upton/Alamy Stock Photo

But on the hip, it’s mostly flies. The jackdaws know they’re there: you can often see one working its way up the roof, teasing and pulling at the reed in search of insects. This, more than hunting for nesting material, is how birds damage thatched roofs.

I peer down and try to spot the flies lurking in the reed. There are at least three species, including huddles of Pollenia rudis, the common cluster fly, which is a familiar sight in attics and window frames over winter. There are also moths and the lime-green translucence of a lacewing. Here, at fly-level, is a forest of reed stalks: row after row of hollow stems to crawl into, and everywhere the glint of bottle-shiny chitin.

2448 - Country diary: the thatch is buzzing with sleepy flies | Environment

Several species of flies lurk among the reed. Photograph: Tom Allan

A gust of brine and tidal gloop blows in from the estuary. I straighten up and look back down at the roof: the insects have vanished again. Now you see them, now you don’t. Insects are easy to miss – perhaps this is why we have lost three-quarters of Europe’s flying bugs before anyone noticed. But here, for now at least, the roof is a giant hive, thrumming with hidden life.

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