538 



ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 



the San Jose scale, however, and fur- 

 nishes a fairly sure basis for identifica- 

 tion in the orchard. 



The condition of the scales can readily 

 be ascertained by scraping them from a 

 branch: if they are dead, the scales will 

 rub off like a dry, gray scurf: if they are 

 alive, the crushed bodies will produce a 

 yellow oil-like fluid which gives the bark 

 a greasy appearance. Wherever a scale 

 has settled there will be a small round 

 spot with a white speck in the middle; 

 the spot is formed by the body of the 

 scale while the white speck is where the 

 long thread-like piercing apparatus, or 

 tongue, was Inserted in the bark. Often- 

 times the scales will completely cover 

 portions of limbs and overlap on each 

 other so that they form a crust. WTien 

 so badly infested, young scales will crawl 

 under old dead scales and settle. We 

 have found as many as four young scales 

 fastened side by side under one old scale. 

 Fruit infested with the scale becomes 

 pitted and gnarled, as the growth is 

 checked at the point where the scales 

 have their beaks inserted. 



"For the benefit of fruit inspectors in 

 particular, it should be noted that reddish 

 discolorations upon yellow fruit are not 

 always caused by San Jose scale. Upon 

 yellow apples and particularly upon 

 peaches very similar spots are produced 

 by attacks of certain minute fungi. Hence, 

 such spots should not in themselves be 

 taken as proof of infestation by the scale. 

 This can be determined definitely only by 

 a careful examination and the actual de- 

 tection of the scale. The presence of such 

 blotches may well arouse suspicion of the 

 presence of San Jose scale and should 

 challenge a careful examination alike by 

 growers, buyers and inspector; so, also, 

 should the presence of dead and shriveled 

 leaves upon the trees in mid-winter invite 

 examination, for, although their presence 

 is not proof of the appearance of the 

 scale, it is evidence that the vitality of 

 the tree has been seriously impaired by 

 some cause, and in regions where San Jose 

 scale is prevalent that cause, in a vast 

 majority of instances, is the scale." (1) 



(1) A. B. roidlev. Bull. 88. Ore. Agi-'l Ex. 

 Sta.. p. G. March. 1906. 



Unlike most other scale insects, it de- 

 velops and hatches its eggs within the 

 body, so that the young are born alive. 

 In Jlay, possibly earlier, under favorable 

 conditions, the females begin to give birth 

 to living young and may continue to pro- 

 duce for six weeks or longer. 



General Description 



The young are minute, light orange 

 yellow, active creatures with eyes, bris- 

 tle-like mouth parts, two antennae or 



rig. 



San .Tose Scale on .\pple I.imb. 

 (Purdue Bulletin 138.) 



