Moths. 1 29 



tube with which they are provided which opens at the 

 surface of the water. Some of these insects are very 

 destructive to vegetation ; the larvae of the common 

 daddy-longlegs for instance, feeds on the roots of grass 

 and will thus sometimes destroy large patches of 

 meadow. The Hessian fly is still more formidable, 

 often destroying whole fields of wheat by attacking 

 the plants when in flower. 



ORDER XI. Lepidoptera, is also a large order, 

 and includes those most beautiful of all insects the but- 

 terflies, characterised by possessing four wings covered 

 with fine coloured scales. These microscopic scales 

 overlap each other on the surface of the wings, and are 

 of different shapes in different species. Butterflies have 

 suctorial mouths (fig. 67), the proboscis-like sucker 

 being rolled up when not in use. The larvae or cater- 

 pillars consist of thirteen joints and are very unlike in 

 mouth, structure, and general appearance to the perfect 

 forms which emerge from them. 



On the lower lip in the larvae of most moths there 

 is the duct of two tubular spinning glands, which when 

 the larva has reached its full size secretes a silken 

 cocoon within which it is enclosed in the pupa state. 



These insects vary in size ; some, as the clothes 

 moths and fur moths, are very small. 



The larvae of the leaf-rollers, a form nearly allied 

 to the clothes-moth, roll up the leaves of plants on 

 which they feed~ into tubes, within which they live 

 and pass their pupa sleep, and whence they emerge 

 in due time as little broad-winged moths. 



Another related form often found on elder trees is 

 the looper or swallow-tail moth, named from the pecu- 

 K 



