126 Insect Pests. 



fall to the ground and bury themselves in it from one up to four 

 inches deep. 



The pupa is encased in a small dull yellowish cocoon coated with 

 grains of earth outside. Larvte which were noticed to fall at the end 

 of ]\Iay had pupated by the 13th of June, and flies appeared on the 

 7th of July. This was the second generation, and these were found 

 to attack larger apples in July and August. Larvss were once found on 

 the 3rd of September. This is evidently very unusual. Very few are 

 found after mid July and most seem to pupate well before then. 



Winter is passed in the larval stage in the soil, pupation not 

 taking place until the spring. 



It is said by some observers that the larvse fall with the fruit, but 

 by far the larger number have been found to fall from it. 



One fact noticed in 1906 and 1907 was, that many of the attacked 

 fruitlets hold on to the trees through the winter, being readily told 

 from the mummified fruits of Munilia by the round holes in them. 



Pkbvention and Tre.vtmext. 



Little can be done when fruit is once struck, but as we know 

 they move from apple to apple, hand-picking the infested fruitlets 

 is worth doing when we see the attack. Spraying with arsenate of 

 lead paste to kill the larvae as they move from fruitlet to fruitlet has 

 proved of no avail. 



Some good has resulted by well working the land in spring and 

 giving a dressing of kainit, but it cannot be called a definite 

 preventive. 



The best results have been obtained by injecting bisulphide of 

 carbon into the soil at the rate of 4 oz. to each tree in eight injections 

 by means of the Vermorel Injector. 



Eemoval of surface soil is, of course, successful, and where a few 

 trees only are invaded is worth doing, but it could not be done in a 

 plantation well attacked. Possibly the sawflies may be trapped by 

 sweet baits, but until much further experiments have been conducted 

 all we can rely on is hand-picking and destruction of the fruitlets 

 in early attacks. Further trials of bisulphide injections should be 

 made. Fortunately this pest seems to work only on bush trees. 



Beferences. 



(1) Westwood, J. 0. Gardeners' Chronicle, p. 851 (1848). 



(2) Ormerod, E. A. 'Handbook of Insects Injurious to Orchard and Bush 



Fruits,' p. 35 (1898). 



(3) Theohald, F. V. The Apple Sawfly, Board of Agriculture Journal, p 183 



(Sept. 1901). 



