Report of State Board of Horticulture. 



ing a single season completely reinfest the tree. Satisfactory- 

 results are obtained only by the most thorough work. Every 

 square inch of surface of trunk, limbs, branches and twigs 

 should be thoroughly covered. By far the most common 

 cause of unsatisfactory results is the failure of those who 

 spraj^ to do thorough work. 



HOW THE SAN JOSE SCALE SPREADS. 



Since the female scale is motionless, and permanently at- 

 tached throughout life to the branch on which it feeds, it is 

 often asked how is it that the San Jose scale can spread from 

 tree to tree, orchard to orchard, and even for larger dis- 

 tances? It is only during the first few hours of its existence 

 that one of these little pests can emigrate, and observation 

 has shown that even then it is incapable by its own efforts of 

 getting more than a few feet from the tree on which it was 

 born. But birds, and bees, and other insects make good air- 

 ships for the little creatures, and no doubt many a young 

 scale has crawled upon the foot of a bird or upon some large 

 insect and thereon voyaged to the distant realm of another 

 tree or orchard. No doubt also strong gusts of wind oftsn 

 tear them loose from the bark on which they are crawling 

 and waft them to the branches of neighboring trees. These 

 are provisions of nature for distributing the species. Through 

 the channels of trade they are carried long distances, even 

 from continent to continent upon infested nursery stock, cut- 

 tings, etc., and probably to a lesser extent upon infested 

 fruit. Buds and scions carelessly taken from an infested 

 tree may transmit the pest to the orchard in which they are 

 placed or may infest an entire block of trees in some nursery 

 and thence be distributed to many orchards. It is also prob- 

 able that many are carried about upon the hands and cloth- 

 ing of the men who prune the trees or pick the fruit or 

 otherwise work about the orchards. 



By such means has the scale been brought from China, its 

 native home, to San Jose, California, whence in thirty-five 

 years it has spread to practically all the fruit-growing States 

 in the Union and to various foreign countries. 



