168 HYMENOPTEEA (SAWFLIBS). 



single egg only is placed on the under-side of each leaf, its 

 position being easily told by the small pale-brown spot on the 

 leaf that appears over it. The ovum hatches in two weeks, and 

 the larva escapes to the top of the leaf. At first it is white and 

 free from slime ; but soon a slimy exudate comes out of its skin 

 and gives it its typical slug-like appearance. The form is 

 peculiar, being much swollen up at the head-end : twenty legs 

 are present in all. In four weeks the slug-worm has reached 

 maturity, when it attains the length of half an inch. At the 

 last moult (the fifth) it loses its slimy character, and becomes 

 dry and dirty-yellow in colour. It then passes down to the 

 ground, where it forms a cell and pupates. In the summer 

 broods, of which there are three in England, the pupal life lasts 

 about fourteen days. It seems that they do not all undergo 

 these stages at the same time, some remaining in the ground 

 much longer than others. liTumbers of larvse are often found on 

 one leaf of different sizes, the eggs having been deposited by 

 different insects at various times. 



Prevention and Remedies. — Similar preventives apply here 



Fio. 74. — Leaf op Cherry eaten by Sluq-wohms. 



as in the Gooseberry Sawfly. Lime will soon kill the larvse if 

 it is applied twice in succession, as they have the power, like 



