Wednesday 4 September 2013

Foreland Brick and Tile Works

Upon Malcolm's suggestion months ago (!) I was keen to visit this former works, once an important industry for making drainage tiles on the island in the nineteenth century. It was a short (and wet) walk, but we saw lots of insects, including this impressive male Common Hawker and a hoverfly I later identified as Sericomyia silentis. Alan Silverside has an excellent page on his website about this species, and I quote therefrom:


With a body length generally of about 16mm, Sericomyia silentis is one of our largest hoverflies (family Syrphidae).
Hoverflies are classic Batesian mimics – harmless but closely resembling bees or wasps (order Hymenoptera). S. silentis is a magnificent but rather fearsome-looking insect that could easily be taken to be a large social wasp (Vespa species). As shown below, it hovers, but it also has a rather 'busy' manner as it moves from flower to flower, again like a bee or wasp.
It is a species primarily of peatland areas and its distribution in Britain matches the distribution of its habitat, i.e. it is most common in the north and west and is much more local and scarce in central and south-east England.
The larva is of the "rat-tailed maggot" type, so called because it has a long, rear, tail-like, extendable breathing-tube, enabling it to live submerged in deoxygenated aquatic sediments. Larvae of S. silentis evidently occur in the rotting vegetation and semi-liquified peat of moorland ditches and flooded peat-cuttings; Verrall (1901) quotes correspondance recording the discovery of larvae that proved to be this species, found where vegetated peat turves had been thrown back into a pool in the cut area.

For his webpage, see http://bioref.lastdragon.org/Diptera/Sericomyia_silentis.html


Foreland Brick and Tile works remains

Sericomyia silentis   

Male Common Hawker

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