202 FOREST ENTOMOLOGY. 



The 2^^'othorax is small, the mesoihorax large, and the metathorax 

 small. 



The abdomen varies according to sex. In the female it may be 

 said there are seven segments dorsally and six segments ventrally. 

 But one segment is concealed ventrally, and other two segments are 

 modified in connection with the ovipositor, thus making in reality 

 nine segments. In the male the abdomen is also composed of nine 

 segments, and as a rule is more slender than in the female. At the 

 extremity the anatomy is somewhat complex, but the general design 

 shows two terminal claspers. 



The legs are long, slender, and covered with scales. The tarsi are 

 five-jointed, and terminating with two small claws. 



The wings of the Lepidoptera are a remarkable feature of this 

 order, inasmuch as they owe their beauty to the often exquisite blend- 

 ing of colour Avhich adorns their surface. This delicate colour is due 

 to the arrangement of minute scales, which overlap one another after 

 the manner of slates on the roof of a house. They form very fine 

 objects for microscopical mounts, and the young collector must always 

 remember their delicacy, as the slightest touch of the finger will at 

 once destroy the beautiful pattern of the wing. 



A detailed study of the wings is of very great importance to the 

 specialist in Lepidoptera, and requires, as a subject, a good deal of 

 consideration to thoroughly understand. The most salient features 

 are the size and form of the scales, the arrangement of nervures, the 

 comparative size of the wing-cells, and the development of the wings 

 during the pupal stage. 



The egg shows great variety in structure, and also in the manner of 

 deposition. In some cases the eggs are large, naked, and exposed ; 

 in other instances they are beautifully coated over with a substance 

 bearing so close a resemblance to the food-plant that it is with great 

 difficulty they can be found, while in other cases it is scarcely 

 possible to discover them at all. There is also great variation as 

 regards the interval of time between the deposition of the eggs and 

 the hatching out of the larvae. Thus, some hatch out in the autumn 

 and feed for a short time, and then hibernate for the winter ; while 

 many, on the other hand, pass the winter in the egg stage, and hatch 

 out only slightly in advance of the development of the food for the 

 larvae. 



The larvce of arboreal - feeding Lepidoptera show considerable 



