40 MISC. PUBLICATION 16 8, U.S. DEPT. OF AGKICULTTJKE 



Thorough cultivation of the orchard during midsummer is of 

 value in destroying the delicate pupae in the soil. The cleaning 

 up and destruction of trash in the orchard and nearby areas are 

 of value, because they render conditions unfavorable for hibernation. 



{m, 201.) 



RED SPOTS 



Aphids, particularly the green-apple aphid, sometimes cause reel 

 spots or specks on yellow or green varieties. These may be confused 

 with the red spots caused by San Jose scale but differ from them 

 in having no light-colored center. 



A red skin spot is particularly common on Yellow Newtown and 

 other green or yellow apples, on the side that has been exposed 

 to the sun. It consists of a narrow reddish halo or band surround- 

 ing some mechanical injury or even the lenticels if these have been 

 torn by the growth of the fruit after they had corked over. Ex- 

 posure to intense sunlight or the penetration of the skin by spray 

 materials also seems to stimulate a localized formation of red color 

 on green varieties or on the green portions of red varieties. Such 

 spots are sometimes mistaken for the effects of San Jose scale, but 

 they can usually be distinguished by their being located at a lenticel 

 and by the fact that they have no white or light-colored center. 



RHIZOPUS ROT 



{Rhizopus sp,, probably R. nigricans Ehrenb. ex Fr.) 



Rhizopus rot is seen occasionally on apples and pears on the mar- 

 ket, but always on stock that has been weakened in some way, as, 

 for example, by overmaturity or by freezing injury. Affected tissues 

 are soft and watery and have a sour smell. 



Rhizopus is a fungus that occurs widely in nature. It is distrib- 

 uted both by contact and by means of its spores and is much more 

 destructive on berries, grapes, and peaches than on apples and pears. 

 It can be distinguished from the other two fungi that most often 

 attack fruits, blue mold (P enicillmvi) and gray mold {Botrytis). 

 by its dark-colored coarse mycelium and the minute white to nearly 

 black fruiting bodies in which the spores are borne. 



Rhizopus rot is not likely to occur on pome fruits if they have 

 been handled carefully throughout the process of picking, packing, 

 and transporting to market. If it becomes established in these fruits, 

 it can be controlled by keeping the fruit temperature below 50° F. 



SAN JOSE SCALE INJURY 



(Aspidiotus perniciosus Comst.) 



The evidence of injury by the San Jose scale most commonly 

 noticed on market apples is the presence of small reddish areas about 

 one eighth of an inch in diameter (pi. 19, A). At the center of each 

 of these reddish areas is usually a light-colored spot, marking the 

 place formerly occupied by the tiny scale insect before it was rubbed 

 off in the handling of the fruit at harvest or later. In depressed areas, 

 such as the calyx or stem ends, the scales may still be present. The 

 scale covering is gray to grayish brown, less than a sixteenth of an 



