AN ECONOMIC ENTOMOLOGY. 



and this may be done more or less completely by mechanical 

 means. As against the larger species — i.e., against all except 

 Agrilus — a wire mosquito netting loosely encircling the trunk, so 

 as not to touch it anywhere, is a complete protection. The in- 

 sects lay their eggs under a bark scale, or on smooth bark gnaw 

 a little hole in which the ^^^ is laid, and if access to the bark be 

 prevented they seek other localities. The wire must be tied at 



Fig. 173. 



The sinuate pear-borer, A^rihis simiafiis. — a, beetle ; h, larva ; c, its anal fork ; d, 

 pupal chamber with pupa in position. 



the top to prevent beetles getting under it, and must extend 

 underground an inch or so. In this way we not only prevent 

 new infestation, but any beetles that may emerge from the trunk 

 will be hopelessly imprisoned and will die without a chance to 

 reproduce. 



Instead of wire netting, tarred paper or even newspapers 

 tightly wrapped around the trunk to the branches will answer 

 an excellent purpose, needing renewal each year, however, where 

 the wire netting lasts several seasons. Thorough whitewashing 



