Raspberry. 357 



It possesses a perennial mycelium, so that when a plant is once 

 infested it cannot be cured. The fungus has two forms which 

 were formerly supposed to be distinct plants. One form is 

 known as Puccinia Peckiana ; it attacks the foliage, and pro- 

 duces spores which germinate in the fall or spring. The myce- 

 lium enters the canes of the host-plant, probably by means of 

 the underground parts, and from there it spreads to the vari- 

 ous branches. The copious production of orange-colored spores 

 on the under side of the foliage of diseased plants is the result 

 of such infection. This condition is preceded by an appear- 

 ance which is easily recognized : the leaves are smaller, and 

 they have a pale green color which distinguishes them from 

 the healthy tissues. 



Treatment. The only practical remedy yet known is to dig 

 out and destroy affected plants as soon as they are discovered. 

 Spraying the foliage with a fungicide to prevent the entrance 

 of the fungus into the leaves might be followed by good results. 



INSECT ENEMIES. 



Cane-borer (Oberea bimaculata, Oliv.). Description. The 

 mature insect is a slender, black beetle about half an inch in 

 length. During June it lays its eggs in the young shoots which 

 grow from the base of the plant. A row of punctures is made 

 above and below the place in which the egg is inserted. The 

 egg soon hatches and the grub begins to burrow downward. 

 By autumn it has reached the roots of the plant. The follow- 

 ing spring the adults again appear. 



Treatment. The puncturing of the young canes when the 

 eggs are laid causes the tips to wilt and on this account the 

 affected shoots are readily seen. They should be cut off below 

 the injured part, and destroyed. The canes should also be 

 watched during late summer, and any which are found wilting 

 should be cut out close to the ground and burned. 



Sawfly ; Raspberry-slug (Selandria Rubi, Harris). Descrip- 

 tion. During May and early in June the raspberry sawfly may 

 be seen among the canes of these plants. It is a black, four- 

 winged fly, the abdomen being tinged with red. The eggs are 

 laid within the leaf, generally near the veins. The larvae are at 

 first nearly white, but later they become dark green and are 

 thickly covered with soft spines of the same color. When 



