Insects, etc., Injurious to the Pear. 337 



by the thorax ; there are ten pairs of legs. When full grown they 

 reach \ inch in length. 



In the last stage the larva is yellowish, with a dry wrinkled skin. 

 Four to five weeks is the usual period of larval life. Specimens 

 kept under observation matured by the 5th of July. On reaching 

 maturity pupation takes place in the earth. The larva spins a parch- 

 ment-like cocoon, to which particles of soil adhere. The depth at 

 which pupation takes place varies from 1 inch up to 3 inches. 



In two weeks I have found a second brood appears, that is some- 

 where towards the end of July. The second brood deposit their eggs 

 in August, and from these the main attack of "snegs" arise and 

 continue to feed well into September and October. At Elstead, in 

 Surrey, I from them in 1898 just falling to earth on the 15th of 

 October. 



The winter is passed in the soil in the larval condition, not as 

 pupae. 



Teevention and Eembdies. 



Where individual trees are affected, in the garden, the plan of 

 removing the surface soU in the winter and burning it will be found 

 invariably to prevent the future appearance of this pest ; but in a 

 plantation, even where cultivated, such could not reasonably be done. 



Sprinkling soot and lime under infested trees when the larvas are 

 maturing has been said to be successful. 



But a remedy will probably be found necessary in most cases. 

 Powdered hellebore has been used with success, so also has soot and 

 lime thrown over the trees with a sulphurator. By far the best 

 method is to spray the trees with arsenate of lead, which is found 

 to poison the " slugworms " very readily, and one dressing only is 

 necessary, as it sticks for some time to the foliage. The paste form 

 is particularly useful in this attack. 



Natural Enemies. 



Cameron enumerates several parasites upon the larvae of this 

 sawfly, namely, Erromenus fumatus, Briscke ; Tryphon gorsTci, Eatz. ; 

 T. ratzburgi, Gorski ; T. etcavatus, Eatz. ; T. transhicens, Eatz. 



On one occasion I watched the Sparrows taking them in numbers 

 off the leaves of a cherry tree. 



Eepbebncbs. 



(1) Cameron, P. ' Monograph of British Phytophagous Hymenoptera,' vol. I., 



p. 225 (1893). 



(2) Saunders, W. ' Insects Injurious to Fruits,' p. 150 (1892). 



Z 



