The Marble Gall Fly. 41 



roots, and the acorns, but of these we have 

 not to do. 



These gall flies belong to the order 

 Hymenoptera, and are provided with a 

 peculiar egg-laying apparatus, with which 

 they are enabled to pierce and eject fluid into 

 the part of the tree chosen for attack. This 

 sets up an irritation in the tissues, which 

 results in the galls so well known to 

 frequenters of our woods and glades. If the 

 gall shows no perforation it may be taken for 

 granted that the grub is in the centre of it, 

 therefore if these are destroyed the grub will 

 be also. The fly usually, however, comes out 

 in the autumn, so that the collection and 

 destruction of the galls, if resorted to, should 

 take place early in the summer. 



The Oak Leaf Roller Moth is an insect 

 which causes great injury to our oak woods 

 and plantations by depriving the trees of 

 their leaves in the early season, thereby 

 materially affecting the health of the tree 

 and the development of timber. Most of us 

 have noticed this in the south of England, 

 especially in some years when the caterpillars 



