INSECTS, 39 



times twelve inclies, and is graduaEy brought outwards again to 

 tlie bark of the tree, but not through it. "WTien the grub has 

 completed this gallery it turns around and retiu-ns to that part of 

 it which is nearest to the heart of the tree ; this part it now 

 enlarges by tearing off the fibre from the walls, and with this 

 fibre carefully and securely closes the entrance, so that if some 

 insect enemy should find its way into the chamber where it 

 passed the first part of its life, that enemy could not enter the 

 gallery to its present abode. At the same time it crowds its 

 sawdust-like excrements into the upper extremity of the gallery, 

 against the bark, thus diminishing the danger of attack from 

 that quarter, and, at the same time, keeping its new chamber 

 tidy. Having thus perfected its arrangements, it again turns 

 around so as to have its head upwards, passes the winter in a 

 torpid state, and in the spring casts off its skin and becomes a 

 pupa, from which, in June, the perfect insect hatches, climbs to 

 the upper end of the ^Hery, tears away the fine sawdust, gnaws 

 a hole through the bark, and creeps forth. 



The larva, when full grown, is about an inch long, and less 

 than a quarter of an inch thick, of a pale yellow colour, with a 

 brown head and black jaws. When there are several of these 

 borers in one tree, they often completely girdle it, thus causing 

 its death. They are distributed more or less numerously 

 throughout the country, and will probably extend in time to 

 those localities that now seem to be exempt, so that no orchard, 

 particularly no young orchard — for young and thrifty trees are the 

 favourite resort of this beetle — can be considered safe from their 

 ravages. It is very important that the trees should be carefully 

 examined three or four times every year, lest these borers effect 

 a lodgment unawares. 



There is a simple method of keeping them out of the trees, 

 and, if this be faithfully employed, they will never effect a 

 lodgment. It has been found that strong alkalies will destroy 

 the vitality of the egg, and, indeed, it is believed that the presence 

 of such an alkali prevents the parent beetle from depositing her 



