to the similar pests found in our apple, pear and orange 

 orchards, have interested me very much. 



You have opened a subject, the importance of which, 

 to the fruit growers of California, can hardly be overesti- 

 mated. The rose scale has been known in the counties 

 about San Francisco Bay for many years past, as one of 

 the worst parasites of the rose bush. 



THE SCALE INSECTS OR BARK LICE 



Belong to the order of the Hemiptera, which includes the 

 true "bugs." The Chinch bug, Squash bug and their 

 allies, are good examples of the order, and are notorious 

 for their evil doings. The Phylloxera is also a worthy 

 representative. The family of the Coccidae includes the 

 scale insects proper. Over thirty species have been 

 found in Great Britain, and it is not likely that California 

 will have to yield anything in point of numbers. A glass 

 of considerable power is needed to study them to advan- 

 tage. 



THE APPLE SCALE. 



The most common apple scale insect is 

 generally known to naturalists as the oyster- 

 shell bark-louse (Aspul lotus concliiformis), 

 named from the form of the scale. Packard 

 says that it does more harm to the apple tree 

 than any other insect known. Prof. Riley 

 also notes its occurrence on the pear, plum 

 and currant. I believe that the first I saw of 

 it in this State was about the Spring of 1865, 

 in Oakland, but it may have been an old 

 settler then. The first cut here given (Fig. i) 

 shows this scale of natural size, as it appears 

 on the apple bark.* 



* For the use of these cuts we aue indebted to the proprietors 

 of the acific Rural Press. 



