May 14, 18158. ) 



JOOBNAL OP HORTIODLTURE AND OOTTAGB GARDENER. 



WEEKLY CALENDAR. 



MAY 14-20, 1868. 



Meeting of Royal and Zoological Societies 

 Meeting of llnyal Institution. 

 Koyal Horti<'nitnral Society, Promenade* 

 4 Sunday afteh Eabter. [Society. 



Anuiveryary Meeting vf Royal Asiatic 

 Royal Horticultural Society, Fruit, Floral, 

 Meet, of So. of Arte, [and General Meeting. 



AveraRe Temperature 

 near London. 



Day. 

 63.2 

 64.8 

 66.2 

 65.7 

 60.0 

 66.5 

 67.0 



Nicht. 

 40.4 

 40.(! 

 43.5 

 41.3 

 42.2 

 42.7 

 43.4 



Mean. 

 61.H 

 52.7 

 54 3 

 63.5 

 54.1 

 54.6 

 65.2 



Rain in 



last 

 41 years. 



Days. 

 16 

 15 

 15 

 16 

 17 

 13 

 19 



San 



Rises. 



m. b. 

 12 at 4 



Sun 

 Sots. 



tn. h. 



42 af 7 



43 7 



Moon 

 Risca. 



Moon 



Sets. 



h. 

 4af 1 



m. h 



48afll) 

 after. 

 51! 



3 

 10 

 20 

 33 



Moon'B 

 Age. 



Days. 

 < 



23 

 24 

 25 

 26 

 27 

 2-i 



Clook 

 after 

 Sun. 



3 51 

 3 50 



Year 



135 

 136 

 137 

 138 

 189 

 140 

 141 



From observationa taken near London during the last forty-one years, the average day temperature of the week is 6:i.6 ; and its night 

 temperature 41.9°. The greatest heat was 89°, on the 22nd, 1847 ; and the lowest cold 25^, on the 15th, 1850. The greatest fal I of rain was 

 0.58 inch. 



■-'•'*^=^''^ OME persons attribute insect-attacks to de- 

 fects in cultivation, and are clamorous in 

 their inquiries as to the cause of plants being 

 so infested with insects. That there is a 

 cause for every effect cannot be disputed ; 

 but that there is any other reason for in- 

 sects infesting a plant beyond that of their 

 liaving in tlic plant attacked some substance 

 which is necessary for their existence is 

 very questionable. I willingly admit that 

 certain conditions are favoui-able to the spread of insect life, 

 and that plants subjected to those conditions favourable 

 to the development of insect life ^^•ill be the most liable 

 to attack. I must, however, differ entirely from those 

 holding insect attacks to be indisputable e\ddence of the 

 plant being in some stage of disease. Disease in a plant 

 is in every sense distinct from a plant being infested by 

 insects, and a plant will perish of the disease by wliioh it 

 is assailed without the occurrence of insects. I know that 

 a vigorous and flourishing plant attacked by insects, if 

 measures be not promptly taken to check their ravages, will 

 be weakened, and lose the beauty of its foliage and flowers, 

 and in the case of fruits these will be deteriorated both in 

 quality and size. I am equally aware of the fact that a 

 plant weakened by an attack of insects recovers its wonted 

 freshness and vigour when freed of the parasites that suck 

 out its juices. So far, then, am I from being persuaded 

 that insects attack a plant because it is unhealtliy or dis- 

 eased that I give them credit for greater instinct, believing 

 them to attack a healthy and vigorous plant oftener than 

 one wliicli is diseased and not so well calculated to meet 

 their wants. 



It is not my intention in this and subsequent papers to 

 treat of the diseases, but of those insects infesting plants, 

 which, if they do not kill, yet greatly impair their beauty 

 of foliage, bloom, or fruit. 



Aphides — Of these there are many species. Abnost 

 every plant subject to the attacks of aphides has its peculiar 

 Mnd or species, and they are of insects the most common 

 and speedy of increase. 



Green Ajihis or Oreen F!i/. — The plainest characteristic 

 of this pest is its colour. It is not very particular as to 

 what it assails. The Pelargonium, especially the Show 

 varieties, the Cineraria, and the Calceolaria, are its great 

 favourites in-doors, whilst the Rose, both in and out of 

 doors, is sure to be visited by it. The Peach, too, sufiers 

 much from aphides, but the species is not the same as 

 those whicli attack the Cineraria, the under sides of Bose 

 leaves, and the growing points of the Pelargonium. Tlie 

 Plum, too, has a green fly peculiar to it : and the Goose- 

 berry, Currant, Beech, Lime, and Sycamore have their 

 own species of aphis, all of which are great producers of 

 honeydew — those infesting the Red and Black Currant, 

 the Lime, Beech, and Sycamore being the most prolific. 

 Honeydew, I may state, is not caused by the influences of 

 the air, and where there are no aphides above there is no 

 deposit of the sweet secretion known as honeydew, of wliich 

 the humble or bumble bees and wasps take their fill, and I 



No. 872.— Vol. XIV, New Seriei 



make a noise in large plantations on a fine day not unlike 

 that of a swarm of bees high in the air. The honey bee 

 does not, so far as I have observed, gather honeydew ; but 

 the wasp will not only suck the honey, but devour the 

 producer of the honey. 



All the species of green aphis are destroyed by tobacco 

 smoke, by a decoction of tobacco in water, and by powdered 

 tobacco. 



For plants under glass the simplest and at the same 

 time the most effectual metliod of destroying the green 

 aphis is fumigation with tobacco. It not only destroys 

 the insect, but acts for a time at least as a preventive. 

 The fumigation should take place on a calm evening, and 

 if the outer air be light and damp all the better. The 

 house should be shut up closely, and where practicable a 

 covering of canvas or mats to confine the smoke would 

 render the fumigation more efl'ectual. The foliage of the 

 plants should be dry, but to prevent any injury to them from 

 the dryness of the atmospliere the floors and every surface, 

 so far as it can be done without wetting the leaves, may 

 be syringed. Nothing is equal to the leaf tobacco for 

 fumigation. Cavendish being the best that I have used. 

 Tliin paper saturated with the juice of tobacco undiluted 

 with water is also useful, and that in which pigtail is 

 wrapped prior to pressing, and when it comes off, is 

 excellent, and when thoroughly saturated quite equal to 

 tobacco leaf. English-grown Tobacco is also good, but 

 not equal to the preceding. The thick paper steeped in 

 tobacco juice much diluted with water is too uncertain in 

 its eft'ects on the green fly, and it will not bum well, nor 

 will it keep without turning mouldy. It is a sure sign of 

 bad quality in tobacco paper or tobacco when either turns 

 mouldy. Then little or none of the active principle of the 

 tobacco is left, and the material bm-ns rapidly, instead of 

 smouldering without much blowmg as in the case of thin 

 paper steeped in undiluted tobacco juice. The paper should 

 be torn into pieces about the size of a crownpiece, and if 

 tobacco leaf be used it should be thoroughly chopped or 

 cut. 



The best mode of making an apparatus for fumiga- 

 tion is to form a piece of sheet ii-on into the shape of a 

 flower pot, and to add to it a copper bottom pierced with 

 quarter-of-an-inch holes. This should be put in about 

 1 inch from the base, and be secured with rivets, as should 

 the joints of the sheet iron. The apparatus may be inches 

 in depth, 7 inches in width at top, and ."» inches at bottom. 

 Under the grating, or bottom, holes shoidd be cut in the 

 sides to admit the air beneath the bottom or gi-ating. and 

 in one side immediately above the bottom should be a 

 hole with a tube of sheet iron, about "> inches long, rivetted 

 to the side, the tube and hole being large enough to admit 

 the nozzle of a pair of bellows. 



Previous to being used the apparatus should be set on 

 the floor, and as near the front of the house as possible ; 

 if there is no floor in front, then set it on a tile or slate. 

 Place a few pieces of red-hot charcoal on the grating, and 

 then a small quantity of the tobacco paper or leaf; apply 

 the bellows, and when well lighted, add more paper or 

 leaf, continuing to add more and to blow gently until the 



No. 1024.— Vol. XXXIX., Old Series. 



