336 



Insect Pests. 



The insects appear in early June in very small numbers, and soon 



commence, if the weather is fine, to lay their eggs. 



Each ovum is de- 

 jjosited in asemicircular 

 slit cut liy the " saws" 

 (it the female im the 

 underside of the leaf, 

 liut now ami then it 

 ^eems to lie laid on the 

 upper surface. A small 

 pale spi:it marks tlie 

 point of insertion of 

 tho (ivnm. 



The egg, \^hich is 

 wliite and (j\'al, liatches 

 in se\'eu days. The 

 young larva escapes iu 

 most circumstances on 

 the upper surface of 

 the leaf. 



It is at first jiale, 

 and after a few days 

 a dark greenish slime 

 OLizes from its skin. 



Four moults of the skin seem to take place. 1 »uring most of their 



life they are 



FIG. 221.— SLLi^WUUMy. 



(The one on the right at its last stage.) ( X 2.) 



bottle-green in colour, dirty jiale yellow behiw, Aory 



shiny and disgusting in appearance ; the hirv;r swe'll out on the 

 front end; the head is hidden in a kind of houd-like mass ttirmed 



