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i I 



have known the latter attack Gooseberry bushes 

 with such severity as to make them look as if they 

 had been scorched. This is very commonly the 

 case on light gravelly soils. 



Red spider destroys the vitality of the leaves, 

 checks growth, and when its attacks are severe, al- 

 together arrests it. It prevents the flowers expand- 

 ing or attaining their perfection, as well as the 

 swelling and maturation of the fruit, and impairs 

 the welldoing of the plant. It likewise, by stop- 

 ping growth, limits the action of the roots, convert- 

 ing a vigorous plant into one which is sickly. 



Predisposing causes innumerable have been as- 

 signed for its attacks, but the principal appear to 

 a dry atmosphere and a high temperature, with too 

 little air at night. Some entertain the opinion that 

 no plant would be attacked by insects if it were 

 healthy ; but I have not yet seen a plant, however 

 healthy to all appearance, that did not become in- 

 fested with some insect. The green aphis is equal- 

 ly partial to a strong shoot of the Rose as to a 

 weak, drawn shoot of the Pelargonium, and it is 

 the same with most insects ; come they do, and 

 whatever they attack is checked in growth, and 

 more or less reduced in health, vigor and fertility. 

 In whatever state a plant may be attacked, whether 

 j weak or strong, the effects are the same ; it be- 

 i comes impaired in health and vigor, and, when 

 I freed from insects, it regains both. Surely, this 

 i does not show that constitutional ill-health and im 

 1 paired vigor are essentials to insect attacks. I be- 

 lieve that they are not induced so much by any 

 peculiar condition of the plant as by the atmos- 

 phere being favorable to the development and in- 

 crease of the insects. Make a plant as unhealthy 

 as we may, it will not be attacked by the insect pe- 

 culiar to it until we also produce an atmosphere 

 favorable to that insect. 



That the red spider delights in and is encouraged 

 hy a dry atmosphere, none having experience of it 

 will doubt ; and it is most abundant where the heat 

 in houses is artiiicially derived from flues or hot- 

 water pipes. I can also affirm, from many j^ears' 

 daily observations, that where there is a plentiful 

 supply of atmospheric moisture, a temperature 

 from fire or natural heat no more than the plant 

 requires, and thorough ventilation, that the attacks 

 of red spider are not grievous. Any one having 

 experience in forcing Vines, Melons, &c., knows 

 how much more liable to the attacks of red spider 

 are the crops obtained by employing great artificial 

 heat than those to which less artificial heat and 

 more air are given ; nor can those who wash or 

 syringe their Peach trees have failed to find how 



free of red spider such trees are, whilst others not 

 syringed are literally eaten up if dry weather pre- 

 vail. A dry atmosphere, too high a temperature, 

 especially at night, and insufficient ventilation, are 

 the conditions under which red spider presents it- 

 self; but there are cases in which it will appear 

 when none of the conditions favorable to its exist- 

 ence are present. Still, the fact of the insect ex- 

 isting may be taken as evidence that the air is too 

 dry, too hot, or imperfectly ventilated. 



The great agent in the destruction of red spider 

 is water, which may not inaptly be termed its na- 

 tural enemy. Water forcibly driven against foliage 

 infested with red spider, will free it of the pest, 

 and that is the best means to adopt in the case of 

 plants which will not bo injured by its application. 

 Syringing with soft water is the best remedy, as 

 well as preventive, which I have tried. Whenever 

 a plant shows unmistakable signs of the presence 

 of red spider, it is well to syringe it forcibly, di- 

 recting the water agamst the under side of the 

 leaves, and this is best done in the evening at the 

 time of shutting up the house, or, if the house is 

 not closed, or the plants are exposed, after the sun 

 has declined in power. Bear in mind that syring- 

 ing once or twice is not of any great avail, but it 

 must be persisted in until the trees are cleared. 

 The only cases in which the uses of water for the 

 destruction of red spider cannot be recommended, 

 are when the trees or plants are in flower, for then 

 a dry atmosphere may be desirable for the setting 

 of the fruit ; and when a tree is ripening its fruit 

 or wood, then a free use of the syringe may not be 

 advisable. When syringing can be adopted, it will 

 be found the very best means for the prevention 

 and destruction of insect ei emies. It is conducive 

 to health and vigor, frees the leaves of dust, and 

 lessens the evils of an artificial or dry atmosphere. 

 It is objected to syringing that it is not natural, and 

 cannot be otherwise than injurious, it being suffi- 

 cient if the atmosphere be kept moist by sprink- 

 ling the floors, walls, &c., and by the evaporation 

 ot water from troughs upon the hot-water pipes. 

 Such may be the case, but I have fiiiled to expe- 

 rience it, having seen the foliage of the Vine brown 

 and ready to fall off by the time the fruit was ripe, 

 and Peaches shedding their leaves before the wood 

 was mature. 



When the syringe cannot be used, then we must 

 look elsewhere for the means of destroying the red 

 spider ; and here I would discriminate between 

 plants which can, and others which cannot, bear an 

 application destructive to the insect. I may in- 

 stance the Vine and Melon as plants to which a so- 



