^2 THE FRUIT GROWER'S GUIDE. 



employed on first infections may save a whole house of black Hamburg grapes from 

 ripening ''red." It is the same with fruit trees, namely : promptly exterminate the 

 originators of the mischief, and pursue a course inimical to the insects. If the soil be 

 dry, water and mulch ; if the atmosphere be dry, syringe or damp available surfaces, and 

 afford those essentials for promoting growth, such as manurial elements, and ammonia 

 vapour, page 65. 



Sulphur used dry on the leaves is no remedy for red spider, but the bisulphide of 

 calcium named at page 248 annihilates the pest. In case of attack whilst grapes and 

 other fruits are ripening, painting the hot-water pipes, heated to 160 or more, with sul- 

 phur, is a certain remedy for red spider. Sulphur begins to vaporise at a temperature of 

 173, and this vapour is fatal to the insects where the air is thoroughly impregnated 

 with it, but it must be used carefully (see "Mildew on Grapes"). Avoid sprinkling 

 sulphur on hot lime. It gives off sulphurous fumes fatal to vegetable life. If the heat 

 is moderate, the fumes may not injure foliage, but the practice is not safe. 



Scale. Few fruit trees are exempt from the attacks of one or more species of scale 

 insects. Some trees are more patronised than others, which points to the need of 

 growers studying the life history of insects so as to more effectually combat them. 

 Scale insects weaken trees, cause them to become sickly and unfruitful, occasionally 

 killing them. Their secretions render the fruit loathsome, and the sticky matter, besides 

 closing the pores of trees and thus doing injury, becomes the seat of a destructive 

 fungus. 



The scales differ greatly in form ; the females are larger than the males. All are 

 developed from eggs packed away below the bodies of the females, and protected by the 

 " scale," even after the death of the parent. The larvse, usually of oval form, have three 

 pairs of minute legs, and are quite active when young. They also possess small antennee, 

 and a beak with which they bore into leaves, fruits and stems, and suck out their juices. 

 When the larvaB " fix " themselves by pushing in the beak they never leave the location, 

 but undergo alteration in structure. The horns, legs, and rings of the body disappear ; 

 thus all power of movement is lost. The insect is protected by a scale-like covering, 

 increasing in size as the Iarva3 grow, and formed by an excretion from the body. The 

 females only are hurtful ; the perfect males resemble small gnats, and are seldom 

 seen. Scales do not increase at anything like the rate of aphides, and rarely produce 

 more than one brood, except indoors, in a season. Their general mode of infestation is 

 represented in the accompanying illustration. 



