RA SPBERRIES INSECTS. 



217 



Duration of Plantations. This depends greatly on the soil, its preparation, and cul- 

 tivation. On the poorest soils, the plants mostly remain on the ground for five years ; 

 on deeply stirred and well-manured land raspberries may last a dozen or even twenty 

 years under good management. The chief points are to make sure of the establishment 

 of the plants before allowing them to bear heavily, sustain them well, and when they 

 show signs of failing make another plantation to continue the supply of fruit. A new 

 plantation should be made two years in advance of discarding the old one. 



DISEASES AND ENEMIES. 



Diseases. Many fungi are found on raspberry canes, but they usually grow on dead 

 parts. One, however, preys on the growing leaves, causing their premature fall. The 

 fungus (Phragmidium rubi Idtei) appears on the lower surface in the form of small 

 dots, usually very numerous. These are at first yellow, changing to dark brown, and 

 the spores reproduce the fungus another year. It is the mycelium that penetrates and 

 feeds on the tissues of the leaves, and the only safe remedy is to pick off those affected 

 and burn them. Poisonous solutions must never be used, as the raspberry is more sus- 

 ceptible of injury from them than any other fruit-bearing plant. The black dots often 

 seen on the upper surface of the leaves are produced by the fungus Stimatea Chsetomium. 

 The leaves first attacked should be gathered and burned. 



Enemies.- -Several insects in their perfect or larval forms feed on the raspberry and 

 their attacks are becoming more frequent and serious. 



The Raspberry Beetle (Byturus tomentosus) is found in most gardens in June, feeding 

 on the pollen and stamens of the flowers and hindering fructification. The larvae 

 bore into and eat the white fleshy cover upon which the fruit is formed and spoil 

 the crop. The beetle is about ^ inch long, yellowish brown, with a thick down ; male 

 rather smaller than the female and slightly greenish. Though provided with large 

 wings the beetle prefers to lie still, often feigning death when disturbed. Eggs are 

 deposited between the stamens of the flowers and hatch in about a week. The larva is 

 about -^ inch long, yellowish brown, with a dark head. It feeds about a fortnight on 

 the receptacle of the frun then gets under the loose skin of the canes or in the crevices 

 of the stakes, spins a cocoon in which it changes to a pupa, from which the beetle 

 emerges the following spring. Preventive measures consist in cutting away the old 

 canes as soon as the fruit is gathered, removing every particle of old wood from the stools 

 in the autumn and clearing off all rubbish for burning. The soil should be scraped 



VOL. III. F P 



