182 



Hull' to h'iKiir tin: San .lasr Scnlr. 

 Terliiips the worst feature of an attack by San Jose Scale is that, 

 owing to its small size and inconspicuous colour it often remains unnoticed 

 until the tree has been seriously injured or even killed. That the tree lacks 

 vigour may be recognized, but the cause of its uuthriftiness is overlooked. 

 Yet it is not difficult to detect when one reall.v looks for it. In the early stages 

 of infestation a few scales may be found, usually clustered about the buds 

 of the preceding season's growth, or even on two-year-old wood. The mature 

 scales are grayish in colour, being usually, but not alwa.vs, somewhat lighter 

 than the bark to which they are so closel.v attached. The immature half-grown 

 scales, which may be found with the mature ones, are at the iiresent time 

 somewhat <larker in colour. 



(Fk:. 08.) 

 Young larv.-p and devoloping scale: in), vontral view of lai'va showing sucking beak 

 with set.T? separated, with enlarged tarsal claw at right: (^t dorsal view of same 

 somewliat contracted, with the first waxy lihiments appearing: ici. dorsal and 

 lateral view -of same still more contracted, illustrating further development of wax 

 secretion; ((M. later stage of same, dorsal and lateral views, showing matting of 

 uao! sccretiuus and first form of youny scale — all greatly enlarged. 



(L. 0. Iloirard and C. L, Marlatt. Bulletin Xo. :l, yen: Series, nirisinn nf 

 EntniHology, V. S. Department of Agriculture. ) 



Tlic mature females are nearly circular in shape, are approximately one- 

 sixteenth of an inch in diameter, and I'ach is somewhat raised in the icntn' 

 to form a slight protuberance or nipiilc which is lighter in colour tlian tlic 

 rest of tlie scale. If this scale is carefully examined by means of a small 

 magnifier, several concentric circles ma.v be observed betwecni the nipple and 

 tlie outside edge ; and if it be carefull.v raised witli the point of a pin or a 

 knife, there will be revealed a minute bright yellow object, the insect itself. 



