August i, 1885,] 



THE TROPICAL AGRICULTURIST, 



95 



fields and pastures new " over the surface of the 

 leaf, leaving the patch on which it previously existed 

 quite dead. Having no feet, it makes use of its 

 strong proboscis for the purpose of locomotion as well 

 as to perform the functions of a mouth, for it appears 

 to be purely suctorial in its larva state. Into the 

 portions of the leaf which remain fresh, this maggot 

 thrusts its proboscis deep into its substance, and, holding 

 on to it as a sheet anchor, drags along its body, cover- 

 ing about the sixteenth of an inch of surface at every 

 pull, and so great is the power which the creature 

 exercises over its proboscis, that on a cardboard 

 surface which it could not penetrate, when the point 

 of the weapon suddenly slipped, the force which 

 was being exerted would roll the maggot clean over 

 on its back. An insect armed with such an instrument 

 as this was not made to live a harmless or innocent 

 life, and during each insertion of its proboscis into 

 the leaf it is doubtless at the same time pumping 

 up the sap for its nourishment, and it may therefore 

 be readily imagined how soon after the maggot has 

 begun to crawl the whole surface of the leaf 

 becomes deeply punctured. The juice (or whatever 

 may remain of it) is shortly evaporated, and the 

 leaf blackens all over and drops off. When the 

 larva is full fed, which it is in about fourteen days, 

 it becomes inactive and enters on the pupa stage, 

 but before this it frequently drops off from the leaf 

 or falls with it to the ground at the roots of the 

 tree where the larvas shelter themselves until they 

 throw off the chrysalis. 



The perfect insect as it emerges from its chrysalis 

 is extremely minute but can be perceived by a 

 good eye unaided. It is oblong, cylindrical, with 

 three legs on each side of the body and a very long 

 pair of antenna, the only ovipositor on the females 

 sharply defined. Body, head, legs and antennte all 

 of a blight silvery lustre. It proceeds at once to 

 attack the young leaves by puncturing a minute hole 

 at -the junction of the midrib and primary veins, and 

 upon any tree which has been badly attacked, to 

 find a single leaf that has not been thus punctured 

 at the root of every vein, is the rule and not the 

 exception. It is now at this stage of my observ- 

 ations where I fail for want of a powerful enough 

 microscope. Do the insects on entering these holes 

 tunnel underneath the scarf skin of the leaf ? If 

 they do, then I have great doubts of the so-called 

 fungus being a fungus at all, but that the yellow- 

 coloured vesicles are the spermatozoids or sperm cells 

 of the male insect which emerge through the pores of 

 the leaf, among which the female deposits her eggs 

 and which she breaks open to fertilize her spawn, 

 On removing the skin of the leaf round these orifices 

 they are also found to contain numerous insects of 

 somewhat smaller size and shape than the full-grown 

 insects, but they posseaa the same color, the same 

 number of legs and long antenniB, and lam under the 

 impression that the in-,eot is at a certain season of the 

 year oviparous and at another vivipsl-ous. 



Whenever a onfficit-nt quantity of epetlmtpisoide or 

 ipirmugohet have become developed, the ftmale Insects 

 tnay be seen issuing frotn the holes and proceed 

 direct to one or more of the powder spo's where 

 they soon get so completely covered wiih the yellow 

 dtist that it is impossible to see inore cf them than | 

 the action of their legs, Lut they can be perceived 

 to bo engaged turning over and buittiig open 

 the yellow-coloured vesicles which v.ry shortly 

 assume a different appearance from whnt they did 

 before the insect operates Upon them. Tbey now 

 become moist-looking andidhere together in detached 

 niasees. Amongst these masses I have observed the 

 female to continue for three days without leaving | 

 the spot, dropping eggs at the rate of three or four \ 

 psr day, covering theai over at the same time with j 



the yellow-coloured matter. The newly-laid egg ia 

 dark brown, oval in shape, with a tail or filament 

 resembling the sperm cells contained within the 

 aiithi'ridia of crijptogamia. They appear to consist of 

 a lymphatic substance, firmly pasted to the surface 

 of the leaf to which the fovilla of the yellow vesicles 

 instantly adheres, so that, if the egg is not observed 

 just as it is excluded, it is imponsible to distinguish 

 it from the general mass, and might possibly be taken 

 at tirst tor a spore of fungi. 



Such is a brief account of the life-history of this 

 insect so far as I have been able to trace it with the 

 appliances at my command. In the hands of a skilled 

 entomologist doubtless much more light is capable of 

 being thrown upon the subject. 



As a body of planters, however, we care little for the 

 life history of the insect : our object is to get rid of it 

 and a remedy is in this case probably more readily 

 found than for many other kinds of pests. It would 

 be much easier to root out the scourge from a whole 

 district than from an individual estate, as, althouoh I do 

 not think that the germ cells can be borne on the 

 wind— they are much too firmly glued to the leaf for 

 i that — still the perfect insect can be carried on coolies 

 clothes from one estate to another. The best thing to do 

 is to destroy the eggs by an acid or boiling water and re. 

 move the medium of the insects' existence for a season 

 As a trial, I selected some time ago, one or two trees 

 the leaves of which were completely covered with 

 larvaj and full-grown insects and had everything 

 in the shape of a leaf snipped off without injuring 

 the buds : in fact, put them under a complete 

 wintering. I then had the stem and branches of 

 the trees as well as the ground round the roots well 

 souced with fresh cattle urine, so that the caustio 

 ammonia might kill any larvaj or insects concealed 

 amongst the crevices of the bark and keep off the 

 small black ants which are often seen covered with 

 the yellow dust. Now a fine flush of new shoots 

 and fresh leaves have sprung forth on which there 

 is as yet no trace of yellow spots or punctured 

 leaves. 



On any estate the coffee of which has been badly 

 attacked, snipping off the leaves will not be a very 

 difficult matter ; but, in order that this proposed 

 remedy should prove thoroughly effectual, it is 

 essentially necessary that an estate should be literally 

 swept of dead leaves, weeds and rotten branches. 

 These all harbor the larva; in the pupa state' 

 and should be carefully collected in bags and de- 

 stroyed. All moss that sticks to the stem or grows 

 iu the ground should be effectually decomposed. 

 Nothing will do this better than caustio lime or 

 caustic ammonia arising from fresh cattle urine. In 

 fact I believe the latter is capable of destroying 

 every kind of living vermin which prey on coffee 

 trees. 



In a letter which I wrote you a short time ago 

 upon the benefits of licjuid manure which I intended 

 as a prelude to this, 1 sent you a plan of a simple 

 method of applying cattle urine or liquid manure on 

 a large scale, but on which you were good enough- 

 Mr. Kditrir, to throw a cold blanket by saying that 

 the cost Would be excessive, whereas I believe Messrsi 

 Walkir & Greig of Badulla could lay the nhole 

 thing down for less than K20 per acre. But in order 

 to convert everything into liquid manure it is neceasary 

 to have a supply of sulpbuiio acid, and I have no 

 hesitation in saying that it would pay a dittrct 

 lite Haputale to have itf own sulphuric acd 

 manufactory, and, if such an idta should be 

 contemplated, I should be happy to furnish Messrs. 

 Walker & Greig with drav. inga of the necessary 

 apparatus which they could construct perhaps with 

 the exception of the Ipaden chambers whiph coulil be 

 got from hyme. 



