St Marks flies

Finding a south facing slope with a patch of bare sandy soil, I sat down on an area of soft hair grass and enjoyed the warmth of the sun, waiting to see what would arrive.

Buzzing overhead was a swarm of large black flies with long hairy dangling legs. These were St Marks flies, which have quite an alarming appearance but are totally harmless as they feed only on larvae and rotting material found in soil.

Swerving in and out among the shoals of these flies was another long legged fly.

Slimmer than the St Marks flies and with long rear legs armed with a curved sickle-like foot, these were leptogasters.

These specialise in seizing others in mid-air and consuming them.

Interesting as these were, they were not what I had come to see.

Emerging from small holes in the sand were solitary wasps.

There are 7,000 different species of these creatures and my skills are nowhere near broad enough to be able to tell which species I was seeing but all were very fascinating to watch.

A few had wonderful iridescent red abdomens while others had striped zebra-pattern legs and antenna. All had lightning reflexes and wonderful flying skills.

Occasionally, I would see a wasp return to its burrow carrying a paralysed grub to feed its larva, found deep within its burrow.

As I watched I realised these wasps may be highly successful predators but they did not have it all their own way, as with a high-pitched whine a bee fly appeared and started to show an interest in the wasps burrows. Bee flies look a bit like bumble bees, hence their names, but as flies they have no stings. The one visiting the sandy patch I was watching had a long slender proboscis which it uses to feed on nectar.

The bee fly was harmless to both the wasps and myself but its young are ferocious meat eaters, which as maggots seek out the young of the solitary wasps and consume them.

As I watched the bee fly move closer to a wasp burrow a flash of green caught my eye.

It was one of Kidderminster's most striking and rare invertebrates, the tiger beetle. This predator lacks any of the guile of the bee fly sprinting across the sand at speeds the eye has difficulty to follow.

The bee fly must have though better than risking an encounter with this ferocious beetle and flew off at great speed. After a few moments the beetle came to a halt and I had the chance to have a good look at this magnificent beast.

It had large, prominent eyes and sharp looking serrated jaws but it was the beautiful striking green coloration of this beetle which was most noticeable.

Then just as I managed a mental "wow!" It was off, sprinting across the sand before just appearing to burst into the air and away on wings which materialised as if by magic.