INSECTS 47 



the countless enemies that surround them, one wonders more 

 and more that may-flies were not long ago extinct. Strangely 

 enough, the may-fly in prehistoric times, long before man 

 started to break in the world, was similar in appearance to 

 the present creature. For in the Devonian and Carboniferous 

 rocks splendid fossil may-flies have been found, certainly 

 astonishing when one considers the frailty of the creature. 



CADDIS-FLIES 



Perhaps one of the most curious and interesting Diptera 

 that spend part of their life in water are Caddis-flies. The 

 adult insect so much resembles a moth that it is often 

 mistaken for such and passed unnoticed. Caddis-flies are not 

 only common in numbers but also numerous in species ; for 

 in Great Britain some 150 different species have been found, 

 and it is more than likely that there a-e still many more to 

 be discovered. 



The adults are characterised in that their wings are covered 

 to a greater or less extent with hair, and that the second 

 pair of wings, which were so diminutive in the may-fly, are in 

 their case larger than the front pair. The antennae, which in 

 the may-fly were short, are usually conspiciously long. In 

 fact it in no way resembles the Ephemera, either in its 

 appearance when adult, or as a larva, or during its life history. 

 Yet strangely enough many a fly-fisherman thinks that the 

 caddis larva is the young of the may-fly. 



The female lays her eggs in the water, whilst resting on the 

 surface. It is, however, said that she will occasionally go 

 beneath the surface, so as to fasten them to chosen spots. 

 She has sometimes been seen carrying the eggs before laying 

 them. The eggs, which number over a hundred, are surrounded 

 by a jelly-like substance, which swells by taking in water. 

 The young after hatching remain for a few days in their " jelly 

 home," and have no sooner left it than they seek what instinct 

 prompts, in the way of building material it may be grains 

 of sand, sticks, leaves, or even the shells of molluscs with their 

 living occupants. 



The case may be built of stones, and supports in the form of 

 long sticks afterwards added. The caddis-worm may choose 

 to build its case so as to resemble a basket-like structure or 

 perhaps, better still, to resemble, as Butler remarks, a number 

 of needles in a partly finished stocking. Some species cut 



