330 TEXT-BOOK OF ZOOLOGY 



When, however, the wings are unfolded, the black and yellow colour of 

 the hind-wings and of the sides of the abdomen give it a very handsome 

 appearance and render it conspicuous even from afar. The caterpillar, 

 which feeds chiefly on the potato plant, is very gaily coloured (yellow or 

 green with oblique blue stripes on the sides). As, however, is also the 

 case in the caterpillar of the Privet Hawk Moth (Sphinx ligustri), these 

 colours do not render the creature conspicuous amid its natural sur- 

 roundings. In the latter insect, the caterpillar is light green with white 

 and violet stripes and red spots on the sides of the body. If this larva 

 be taken up in one hand and a twig of privet be held in the other, the 

 caterpillar appears very conspicuously coloured. Anyone, however, who 

 has ever searched for these insects knows how inconspicuous their garb 

 renders them ; for the varied tints of green of the leaves, and the alter- 

 nations of light and shade, bring about such a change of colour that it 

 is extremely difficult to discover the insects. The hind-wings and sides 

 of the abdomen of the privet hawk-moth are black with red stripes. 



The Pine Hawk Moth (Sphinx pinastri) is exactly of the colour of 

 the bark of pine-trees, on which it is in the habit of resting. Two other 

 well-known Sphingidse, the Eyed Hawk Moth (Smerinthus ocellatus) and 

 the Poplar Hawk Moth (Sm. populi}, while resting hold their wings 

 more away from the body, and then bear a striking resemblance to dry 

 leaves. (Observe the metamorphosis of the species mentioned. Explain 

 their names.) 



Families 2 to 4 : Wood-Borers (Cossidae) ; Burnets (Zygaenidae) ; 

 Tiger-moths (Arctiidae). 



1. The large flesh-coloured caterpillar frequently found in soft- wooded 

 trees (willows, poplars, fruit-trees) is the larva of the Goat Moth (Cossus 

 ligniperda). Like all wood-boring insects (examples), it possesses powerful 

 masticatory pincers. As it feeds on substances containing but little 

 nutriment, the larva takes two or three years before it is full-grown. 

 The moth is nocturnal, and hence its colours are obscure (grayish- 

 brown with white and black spots and sinuous lines). In the daytime, 

 while resting with wings drawn up against the trunk of a tree, it bears 

 a striking resemblance to the bark or a dead branch. 



The larvae of the Clearwings (Sesiina) are likewise wood-borers. 

 The wings of the moths are for the most part devoid of scales, and 

 therefore are of glassy transparency. The most familiar species is the 

 Hornet Clearwing (Trochilium apiforme), which in shape and colora- 

 tion closely resembles a hornet, and like the latter, too, flies by day. 



2. On blossoms, especially those of the scabious, moths, with their 



