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THE TROPICAL AGRICUL'fURlS*. [March i, 1886. 



the plants were weak aud sickly, aud that they were 

 sutl'ering from root fungus or somu other -^lisease long 

 before the ants commenced their depredations. This 

 opinion coincides not only with tlii*. observations of 

 Firoaingev and other Indian authorities, but also of 

 Figuier, Smeathman and many eminent naturalists who 

 haTe made the Termiteif their special stud}'. It would 

 be impossible for us to describe in detail the innumer- 

 able unwelcome visitors that are found in our gardens, 

 but must content ourselves with briefly describing the 

 most importLint of them — either insect, reptile, bird. 

 or beast, and the most ettective means that can be 

 employed for their extirpation. "We will commence 

 with the insects, for these, though individually are 

 generally so insignificant, collectively form some of 

 the most powerful enemies that we have to encounter. 



APHIDES. 



In this family there are supposed to be upwards of 

 one hundred aud fifty species ; many of these, it is 

 stated, confine their attention to one plant or family 

 of plants, such as Aphis Innr/era, better known as 

 the *' American blight.'' which restricts its operations 

 exclusively to the apple tree, and Apltis fabtr, which 

 is only found on the B:-oad Bean. Other species, how- 

 ever, are far more cosmopolitan in their ideas, and 

 will attack almost anything that come within their 

 reach. The most common of these is Aphis msoi, better 

 known as green-fly or plant lice. These not only 

 attack Koses, but almost any other plant ou which 

 they can etfect a lodgement, and if ne£,'lected ■ for a 

 few days increase enormously. The young shoots of 

 Roses and other trees all round their circumference 

 for the length of upwards of a foot are often covered 

 with this .species; they remain crowded against each 

 other, aud sometimes there are two layers of them. 

 If carefully observed, without moving the plants, they 

 will, to all appearance, be tranquil and inacti\'e, they 

 are however gratlually, but surely, absorbing the vital 

 powers i)f the plants, piercing with the point of their 

 trunk the epidermis of the leaves or stalks aud draw- 

 ing from them the .sap they contain. Infinitely small 

 as is the proboscis of the plant louse, when there are 

 thousands of these creatures crowded on the stems or 

 leaves of a plant it must evidently suffer. Tho enorm- 

 ous rate at which the aphis family increase under 

 favourable circumstances seems almost incredible. 

 Bonnet, a celebrated naturalist, gives the results of 

 experiments ma'ie by him to prove how rapid is the 

 multiplication of aphides; he says : — "A single female 

 produces generally 1>0 young ones; at the second gener- 

 ation these 9U produces 8,lU0, these give a third gener- 

 ation which amounts to 7-r»,0;»0 insects ; these in 

 their turn become 65,(>10,(JUU; the fifth generation 

 consisting of 590,490,000 will yieUl a progeny of 

 53,l4"J.li)0,O0O ; at the seventh we shall thus have 

 4,;ML'.".Sl),O00,ti00, ; and the eighth will give 4-U,4(il, 

 OlO,tj(tO,U0O. This immense number increases immeas- 

 urably when there are eleven generations in the space 

 of a year. Fortunately a great many carnivorous in- 

 sects wage fierce war against the plant lice and destroy 

 immense numbers of them. Thus they are held in 

 check, and kept from multiplying inordinately." 



Smee in his comprehensive work, Mii Garden, in 

 discusbing this subject, says :— " We are In the habit 

 uf looking to astronomy for numbers beyond the 

 capacity of man to realize, but the multiplication of 

 Aphuhn atford a more astounding illustratiou. To 

 represent the number of the progeny of one of these 

 creatures for the space of one year, thirty-six figures 

 placed in a row would be required. As the distance 

 in miles between the earth and the sun is represented 

 by only eight figures, and as seventeen figures would 

 represent the number of Aphides required to form 

 a line between the same bodies, we may form a kind 

 of indefinite vision of the immensity of the power 

 of multiplication possessed by Aphith\^^ and have a 

 dim idea of the rapid manner in which they can 

 cover vegetation when thoy appear." 



In Europe there are several instances on record in 

 which bwarms of these insects, frequently miles in 

 length and breadth and sufficiently dense to obscure 

 U»yHgbt, have been ob^f^rved. We are uot aware if 



any similiar occurrence has been noted by daylight 

 in this country, but in Calcutta and the surrounding 

 districts each year, just at the setting in of the 

 north-east monsoon, we have a very similiar pheno- 

 mena. At this period, for several nights in succession, 

 the air is filled with a species of Aphide, these are 

 particularly attracted by any artificial light, and 

 in the vicinity of street gas lamps the crowd is fre- 

 quently so dense as almost to obscure the light. This 

 attraction leads them to their own destruction, 

 for the heated air surrounding the lamps proves 

 fatal to them, and in the mornings following 

 these visitations they frequently cover the ground 

 to a depth of two or three inches for several feet 

 around e;ich lamp. On one occasion, some two or 

 three years since, they appeared in such numbei's as 

 to stop the performances in our local Theatres. 

 "Whether these myriads migrate at night only it is 

 difficult to say. "NVe can hardly think that s«ch is 

 the case: probably the stream is a eoutiuuous one, 

 but in the daytime they fly at a height beyond the 

 power of human \'ision. AVhere these immense shoals 

 come from, and whither bound, seems clouded in 

 obscurity. It is a strange fact, however, that in their 

 migrations they have never been known to attack 

 vegetation. It is very fortunate for us that such 

 is the case, otherwise we should have as much cause to 

 dread their visitations as that of a flight of locusts. 

 Innumerable recipes have been recommended for the 

 destruction of green-flv. some of them, unfortunately, 

 proving just a? elfective in destroying the plants as 

 the insects with which they are infected, in the 

 hands of an inexperienced operator. In the use of 

 insuctitudes we nuist always take into consideration 

 the constitution and nature of the plants to be 

 operated unon : with hard-wooded plants having well 

 ripened growth we may use thera much stronger 

 than with those of a succulent nature, or where the 

 wood is yo'mg and tender. "With the former cbss 

 of plants one application mny thoroughly overcome 

 our enemy, but with the latter it may be necessary 

 to give three or four weak dressings at intervals of 

 a week or ten days. The following are some of 

 the most reliable remedies than can be employed 

 for eradicating this pest. 



I. iSoft iSna/i and Tobacco. — Dissolve one pound of 

 soft soap in three gallons of water, and when eooi 

 add one qurrt of strong tobacco water. Small plants 

 in pots should be immersed in the mixture, bottom 

 upwards, and hold in it for a minute or two, taking 

 care that the. soil is uot ulso submerged. When taken 

 out allow them to stand about ten minutes, after 

 which syringe with clear water till every insect has 

 disappeared. Plants in the ground, or such as arc 

 too large to bo dipped, should be thoroughly syring- 

 ed with the mixture and af terwarils with clean water. 



II. Sflphi'v JH.cturc. — Four ounces sulphur, four 

 ounces powdered tobacco, four ounces quicklime and 

 eight ounces of soft soap in three gallons of water. 

 This is ouly suited for hanl-wooded plants, which 

 siiould be well syringed with the mixture aud then 

 allowed to remain for twenty-four hours, after which 

 they must be thoroughly cleansed with water. 



III. Soda and Ahee. — An American horticultural 

 journal gives the following preparation as sure death 

 to the gi-eeu-fly, aa well as many other insects that 

 infest house plants: — Dissolve '2 lb. of washi.g soda 

 and 1 oz. of bitter aloes, and when cold add one 

 gallon of water. Dip the plants into this solution 

 and lay them on their sides for a short lime, and 

 the insects will drop oiT. Hyriuge the plants with clean, 

 tepid water, and return them to the house. This 

 mixture proves to be an effectual remedy for vermin 

 on wall trees aud hard-wooded plants of robust 

 habit, but injures soft-wooded plants and tender 

 newly-grown shoots of all plants. 



IV. Tobacco Potrdtr. — This is one of the most certain re- 

 medies than can be employed for the destruction of green- 

 fly. Procure ordinary country grown tobacco, dry tho- 

 roughly and then pulverize as finely as po.*isibler 

 procure a common powder puti or a cook's flowe ; 

 dredger, aud after baviiig first damped the plantpf 



