The Apple Sawfly. 



187 



still on the tree, the pupae were found in the soil beneath. 

 Moreover, on two occasions, the larvae have been observed 

 to wriggle out of the hole at the side of the apple and fall 

 to the ground. No doubt some fall with the fruit, but only 

 a small percentage. The large hole to the exterior in the 

 infested fruit is very distinctly seen, especially by the 

 "frass" and moisture running from it. This and the 

 position of the insect in its pupal condition are the two points 

 of economic importance to be noticed by orchardists. 



Prevention and Treatment. 



Little can be done in this attack when the pest 

 have once taken up their abode in the fruitlets, 

 but, as we know, they migrate from one apple to 

 another, it is certainly worth while in young plantations 

 to pick off the diseased fruitlets and destroy them. Spraying 

 would do little good, although it would, of course, if arsenites 

 were used, prevent the grubs from entering fresh fruits, but 

 hand-picking is far preferable when the trees are small. The 

 only other thing to be done is to destroy the larvae in 

 the winter when they are buried in the cocoons under the 

 soil. These may be got rid of by well working the soil 

 beneath the trees that have been invaded with a prong hoe, 

 and then dressing the ground with gas lime or kainit. 

 Better still would it be to remove three inches of the soil just 

 round the trees, and burn it during the winter. Unless this 

 is done or the apples that are invaded are collected and 

 burnt with the grubs in them the attack will continue from 

 year to year in the same orchard. 



No natural enemies of this Sawfly are known, but probably 

 poultry kept in the orchard would destroy these insects in the 

 larval and pupal stages, just as they do those of the Codling 

 Moth, Winter Moth, and others. 



