FRUITS 255 



visible without the aid of a strong pocket magnifier. 

 It scarifies the surface of the leaves, young twigs, 

 and the fruits, causing blackish thickenings and 

 discoloration of the leaves and twigs and a peculiar 

 bronzing or russeting of the fruit. These " russet " 

 oranges are well known to the trade and by many 

 are supposed, like russet apples, to represent a distinct 

 variety. This is not the case since all varieties 

 become " russets " when attacked b}^ the rust mite. 

 The damage is entirely external and does not injure 

 the flavor of the fruit. In fact, many people believe 

 that the russets are the sweetest. They do not look 

 as well, however, and " russets " ahvays bring from 

 fifty cents to a dollar a box less than " brights " of 

 the same grade. This mite, like most others of its 

 class, is very susceptible to sulphur fumes. It can 

 be quite successfully controlled by dusting the trees 

 with sulphur, or better still spraying with water 

 containing a little flour paste and flowers of sulphur 

 in suspension. Spraying with sulphide of potash is 

 also very effective^but the effect is less lasting. The 

 treatment should begin very early in the season and 

 should be continued from year to year. 



Scale insects of various kinds are among the most 

 troublesome pests of the orange. There are a consider- 

 able number of species, but they cannot be considered 

 separately here. When present in considerable num- 

 bers on tlie trunks, branches, or leaves, they greatly 

 reduce the vitality and productiveness of the tree. 

 Young trees may even be killed outright. The fruit, 

 too, is much disfigured when covered by scales. Very 

 fortunately most of the scale insects have numerous 



