316 PYRUS MAM >. 



lure; ami (ho romcdy. or palliative, in such soils, is hniiiig ahiiiulantly, to ncu. 

 trahzo the Dxidc : and plaiitiiiiir on tlio siirfa(!c. without (HiruiiiLj the i^'roiiiid, hut 

 only hoeiiii;, or keepiiii; ii entirely in pasture. The trunlc and lirauelies. in sonic 

 soils, and in moist situations, are liahlc to he infested with liilnns and moss, 

 whieh must be scraped oil'; and in others, the mistletoe is apt to take root, which 

 must be cut out. 'IMie fuuirus, yKcidiuni caiicellatuni. which also sirows on the 

 leaves of the pear-tree, and produces what is called mildew, is not unfri-'([nent on 

 those of the apple-tree. 



The leaves, llowers, fruit, and Avood of tlic apple-trcc arc subject to the attacks 

 of numerous insects, or tiicir larvic, against which there arc few or no remedies. 

 ()ne of the most eonnnon enemies to this tree, in liUropc, particularly in l-hii^land, 

 is the cotton insect, or woolly aphis (^A/)his lanif^crn, of Linnaeus, and Eriosoma 

 mnli, of liCach.) This insect was first descril)cd by llausmanu, in lSf)l. as infest- 

 ing the orchards of CJermany : but it was noticed in Mugland as early as the year 

 1787, and has since acquired in that country, though improperly, the name of 

 "American blight," from the belief that it had been imported from America. 

 Although it exists in the United States, it is exceedingly rare; but it is thought 

 not to be indigenous, but was brought to this country on fruit-trees from Europe. 

 It appears to have been known, also, by the French gardeners for a long time 

 previous to either of the above-named dates ; and according to Mr. Rennie, it is 

 found in, the orchards in the vicinity of Harflcur, in Normandy, and is very 

 destructive to the trees in the department of Calvados. The eggs of this insect 

 are so small that they cannot be distinguished without the aid of a microscope. 

 They are enveloped in a cotton-like substance, furnished by the body of the 

 insect, and are deposited in the forks of the branches, and in the chinks of the 

 bark, at or near the surface of the ground, especially if there are suckers springing 

 from that place. The young, when first hatched, are covered with a very short, 

 fine down, and appear, in the spring of the year, like so many little specks of 

 mould. As the season advances, and the insects increase in size, their downy 

 coats become more distinct, and grow in length daily. This down is very easily 

 removed, adheres to the fingers, when touched, and appears to issue from all the 

 pores of the skin of the abdomen. When fully grown, the insects of the first 

 brood are one tenth of an inch in length, and, when the down is rubbed off, the 

 head, antennse, sucker, and shins, are found to be of a blackish colour, and the 

 abdomen of a honey-yellow. The young are produced alive during the summer, 

 are buried in masses of the down, and derive their nourishment from the sap of 

 the bark and of the alburnum or young wood directly under the bark. The 

 adult insects, it is said, never acquire wings nor honey tubes, but from time to 

 time, they emit drops of an adhesive fluid from the extremities of their bodies. 

 Although destitute of wings, they are conveyed from tree to tree by means of 

 their long down, which is so plentiful and so light, that they are easily wafted 

 by the winds of autumn, and thus the evil will gradually spread throughout an 

 extensive orchard. The numerous punctures of these insects produce on the ten- 

 der shoots a cellular appearance, and wherever a colony of them is established 

 warts or excrescences arise on the bark ; the limbs thus attacked, become sickly, 

 the leaves turn yellow and drop oft'; and, as the infection spreads from limb to 

 limb, the whole tree becomes diseased, and eventually perishes.* A writer in 

 the London " Entomological Magazine" describes the mode of propagation of this 

 insect, and gives a method of destroying it as follows: " These blights wander 

 wherever it pleases the wind to carry them ; and, if bad luck should drive one 

 of them against the branch of an apple-tree, there it will stick, creep into a crack 

 in the bark, bring forth its young, and found a colony. The white cotton soon 



* See Harris' Report, p. 193. Also Illiger's Magazine, i., p. 440 ; and Rennie's Insect Miscellanies, 

 p. 180. 



