372 



FARMERS' REGISTER— APfllS LANATA— FRUIT TREES. 



APHIS LANATA. 



The jJphis lanata, nicknamed without reason the 

 Jlmerican blight, is a minute insect which is doing 

 great injury to the apple orchards in Great Britain, 

 and is extending itself in this country. In the 

 June No. of the Gardener's Magazine, there is a 

 collection of facts and prescriptions in relation to 

 this pest, which it may be of use to notice. 



" The blights wander wherever it pleases the 

 wind to carry them ; and if bad luck should drive 

 one of them against the branch of an api)le tree, 

 there it will stick, creep into a crack in the bark, 

 bring forth its young, and found a colony. It has 

 just the look of a bit of cotton, or a downy seed. — 

 If you examine it you will find it to be just like the 

 plant-louse, which infests our rose trees, &c. ; but 

 unlike all other plant-lice, it is closed and muffled 

 up with cotton wool, in such quantities, that at first 

 you would have no more idea that the lump con- 

 tained an insect, than that the mass of cloths on a 

 stage-coach box in winter, contained a man. The 

 white cotton soon appears in bunches ; branch after 

 branch becomes affected ; the tree grows cankery, 

 pines and dies," from the exhaustion of sap caused 

 l)y these insects. 



We have seen this aphis only upon nursery 

 trees, and there they located themselves generally 

 at the intersection of branches. Tubercles or 

 knots soon appeared upon the bark where they had 

 fixed, and on taking up the trees we often found 

 they had extended their colonies to the roots, as in- 

 dicated by strings of tubercles resembling the an- 

 bury in turnips. The remedy we employed for 

 two seasons, which was a faithful application of oil, 

 with a rag, to their nests, seems to have destroyed 

 them, ?i.s well at the root as on the branches, as 

 they have hardly met our eye for the two last years. 

 The rains, it is presumed, carried the antidote to 

 the roots. 



Various remedies for the evils tlic insects inflict 

 are mentioned in the Gardener's Magazine. One 

 writer recommends a mixture of whitewash and 

 size, to be applied to the tree, warm, with a brush. 

 Another, diluted sulphuric acid, three-quarters of 

 an ounce measure of the sulphuric acid with seven 

 and a half ounces of water, applied to all the cre- 

 vices with a rag. This also destroys lichens and 

 other insects and their eggs. The sublimate of tar 

 is recom.mended by a third, applied with a pain- 

 ter's brush ; train oil by a fourth ; oil and soot 

 by a fifth] a strong infusion of tobacco by a sixth, 

 &c. &c. 



The best topical application which we have ever 

 applied to the apple tree, whether to destroy insects 

 or parasitical plants, or to impart health and vigor 

 to the tree, is a very strong ley of ashes or potash. 

 It destroys the bark louse and the larva of other 

 insects, and gives to the bark a smoothness, elasti- 

 city and freshness which no other application gives. 

 We apply it the latter end of May, and have not 

 repeated it oftener than once in three years. 



B. 



SEEDLINGS FROIM GRAFTED AND UNGRAFT- 

 ED FRUIT TREES. 



An opinion prevails that seedling peaches, plums, 

 &c. will yield fruit exactly resenibling the parent, 

 provided the old tree was not grafted, — and pro- 

 vided the jojYs be kepi moist until planted, —to which 



some add, if the fruit be planted whole; that is, 

 with an unbroken skin, and all the pulp left sur- 

 rounding the stone. 



As mankind are generally best satisfied with a 

 reason for every thing, we will endeavor to inquire 

 into the cause of such rules — the ivhy and the 

 loherefore — and begin by putting the question, 

 fVhy should the offspring of a grafted tree, stand- 

 ing on another's root, be more likely to prove a new 

 variety than the offspring of a seedling tree stand- 

 ing on its oivn root? 



It has become a common opinion that new kinds 

 of fruit originate from the pollen of one variety be- 

 ing carried by the bees or by the wind, to the stig- 

 ma of another variety ; and the offspring, partak- 

 ing of the nature of both parents, must, in conse- 

 quence, be a new variety. That this is very likely 

 to happen amongst crowded trees of different kinds, 

 will be readily admitted; and the experiments of 

 Knight and Fan Mons, tend to confirm it. But 

 if a grafted tree stands too remote from other va- 

 rieties to be affected in this way, the offspring could 

 not change on this principle ; and might not change 

 at all. It will thus be seen that proximity to other 

 trees, requires to be considered. Another question 

 will then occur, j^re the stigmas of grafted trees 

 more liable to be fertilized by other varieties, than 

 the stig7nas of ungrafted trees 1 We could not 

 affirm it. Hoiv then can the offspring of a graft- 

 ed tree be more liable to a change ? We know not ; 

 for whether the stock affects the graft by its sap, 

 or not, — it cannot affect it by the pollen when it 

 produces none. 



A fourth question is now presented. Does an un- 

 grafted tree produce seedlings exactly like itself 7 

 Thirty years ago, when we had scarcely any 

 other kind than the old Indian peach in the country, 

 it was observed to come very true from the stone ; 

 and. amongst the hundreds of trees produced in this 

 way, we have not met with any distinguishable 

 sub-variety. It has been the opinion of some hor- 

 ticulturists however, that inferior varieties are more 

 permjinent and less liable to change in their off- 

 spring than superior varieties, — as if the latter had 

 ascended lo the top of the wave, with ^ 3trong ten- 

 dency at the first change to fall back to the origi- 

 nal level. We lay no great stress on this idea, 

 though it may merit a passing notice. However, 

 if in the beginning of things there was only one 

 sort of peach, it follows of necessity, that it or its 

 offspring must have spread into varieties unassist^ 

 ed ; and we know from observation, that a plant, 

 solitary, and remote from any other of its species, 

 has in a few years passed into several varieties. — 

 There are other causes then, besides the access of 

 pollen to the stigmas, for such changes ; but in ad- 

 dition, when ungrafted trees grow in close assem- 

 blage with other kinds, it is very doubtful if the 

 young trees will prove true. We have seen seve- 

 ral kinds of peach trees crowded together in a small 

 gai'den ivithout budding, that varied much in their 

 offspring. Among them was a white peach of very 

 peculiar properties which could be readily traced 

 in its descendants; but there were no two exactly 

 alike. 



It remains for us to speak of planting the stones 

 in a recent state, while the whole or a part of the 

 pulp remains attached. If we examine a peach 

 stone in its freshest state, we find the pit a kernel 

 no longer fast to the inside of the stone, but gene- 

 rally a little shrunk, and loose in its cavity. It ig 



