Water Wildlife

                            Caddis Flies      

There are over 3000 species of Caddis Fly - more correctly known as Trichoptera.  They all tend to resemble moths, but often have almost translucent wings.  The name comes from the Greek thrix, a hair, and pteron, wing.  Look with a magnifying glass, and you will see a very fine layer of hair over both body and wings.  They are usually of more delicate proportions than the majority of moths, but it is their feelers that distinguish them in general, as they are always very long.  Beyond these common features there is a very wide variance of colour and size within this group of flies.  They are harmless creatures which do not sting.  There is a variance in habit between different species of Caddis Fly, as some are inclined to be solitary creatures, whilst others might be seen flying  in the trees, or gathered near the water, in small swarms.

The Caddis Fly begins life as a tiny egg, often visible on leaves or edge of pond near the surface.  The eggs are layered in jelly surrounded clusters, and actually look very much like the eggs of the Harlequin Fly - a little fly that swarms to dance in a cloud over the water. 

The stage of the Caddis Fly's life that most of us are more familiar with, however, is the larva stage.  The Caddis Larvae, or worm, has a soft body which it coats with a silk web and grains of sand and grit, pieces of chewed off plane and stalk, etc.  Some look a little like tall, narrow, stone chimneys, others like tubular log cabins - depending on whether they live among the plants or on the gravel floor.  It is not by luck that the shell so made is exactly the right length for the larva - sensory tips on the end of the tail are used to measure the case for size!  At the first sign of danger the larva can retreat inside it's tube, which provides it with camouflage and armor plating.

The Caddis Larvae require a large amount of oxygen, in general, and so tend to frequent streams and rivers rather than ponds.