132 



THE BRITISH NATURALIST. 



[June 



in such situations the pest is generally allowed to remain unmolested 

 for years ; indeed, it often happens that the grower, whether cottager 

 or professional, is wholly ignorant of the presence of the disease. 



I need hardly add that in such cases the bushes are veritable 

 pest-places for the dissemination of the disease. Its rapid spread of late 

 years is undoubtedly due, in great measure, to the propagation of 

 diseased cuttings ; these latter are only too often sent into fresh 

 districts, and I feel sure that by this means alone quite 50 per cent, of 

 new colonies are established ; this statement I make with the greatest 

 confidence, as instances have come under my own observation. 

 I well remember a gardener who recommended cuttings from his 

 infested bushes on the ground that they produced the finest fruiting 

 buds he ever saw. The so-called "fruiting buds " were every one of 

 them infested with the mites, and consequently were worse than 

 useless. In making these statements I do not wish to imply ignorance 

 in the whole fruit-growing fraternity. There are those who have done 

 all 'that lies in their power to stamp out the disease in this district. :;; 

 Six years ago, when attention was first called to this pest at 

 Chester, there were very few gardens in the immediate neighbourhood 

 that did not contain diseased bushes ; now, in the gardens of the thrifty 

 it is difficult to obtain specimens for lecturing purposes. 



APPEARANCE OF THE DISEASED BUDS. 



There is not the slightest difficulty in recognizing the disease, for 

 every infested bud becomes aborted and swollen, and in bad cases 

 they are often three or four times as large as the healthy fruiting buds ; 

 a glance at the plate will at once show the difference. A perfectly 

 healthy branch is shown at Fig. 1, and diseased branches at Figs. 

 2, 3, and 4, and a X is placed opposite the diseased buds that they may 

 be more readily identified. 



THE CAUSE OF THE DISEASED BUDS 



is due to the presence of an exceedingly small species of mite, belong- 

 ing to the Phytopti. So small are the mites that they are scarcely ever 

 visible to the naked eye, and when examined with a pocket lens they 

 only appear as a white mealy substance in the buds. On examination 

 with the microscope they appear as shining semi-opaque objects, 

 very elongate, and having four legs, which carry them rapidly over 

 the surface of the leaves. In winter they are frequently found 

 anchored into the tissues of the embryo leaves, by means of a pair of 

 stiff bristles situate at the anal extremity of the body. I have never 



* I may specially mention the good work done by the Cheshire County Council, and 

 by the Committee of the Grosvenor Museum, Chester. They have instituted classes, 

 and have given free lectures on the various pests injurious to farm, fruit, and garden 

 crops. 



