©4 The Tea insects of Indic 



find live insects. On 16th April it was noted that red spider was to be seen in all 

 parts of tbe garden except the sulphured area, while neighbouring gardens were very 

 much affected by it. The sulphured area was tlie first pruned and should, under 

 ordinary circumstances, have been the most affected. With regard to the effect of 

 the sulphur treatment on mosquito blight, some mosquito blight insects were caught 

 and experimented with on 23id i\Iiirch. VVhen sulphur was powdered on to them it 

 adhered to the hairy parts of the body and legs to a considerable extent, but the insects 

 did not die at once, though putting them in this state under a glass in the sun was 

 fatal to them. After applying the sulphur all signs of blight disappeared, careful 

 search not revealing a single punctured shoot. It must be added that little blight 

 eould be found on other parts of the garden, but the flats which had been treated with 

 sulphur were always the ones to be first attacked.' 



6tk May 1S92.—'" I have no objection whntever to Mr. Cotes making use of any inform- 

 ation he may have derived from my writings, and will te glad to supply him with further 

 notes from time to time. I strongly object, however, to trying Mr. Cotes' suggestion about 

 sulphur soap instead of the pure sulphur (except as a supplementary experiment) for this 

 reason.^ 



" The action of sulphur against red spider is now proved beyond doubt, and requires no 

 comment. It also seems to have killed off tbe blight insect ; and if this is a fact it would 

 be a vast pity to operate against the one disease without the other in future, for tbe sulphur 

 soap wash, however efficacious against spider, could not be expected to do much harm to a 

 winged insect like blight. Moreover, the wash requires special apparatus for application, 

 and the purchase of such insufficient quantity to go over hundreds of acres quickly would 

 be prohibitive. That blight has actually been killed out over the sulphured area seems to 

 me a certainty. On the 14th March I wrote to you saying that my original plan of dis- 

 tributing the sulphur had been changed owing to a considerable amount of blight being 

 noticeable. This is proof that blight tvas there ; it is equally certain there is none noiv, and 

 the accompanying extract from my diary will prove that during the past ten years I have in- 

 variably reported blight not later than the week ending the 23rd April, and almost always 

 in the same spot, which this year is free, I am not yet in a position to ask you for a 

 further and larger supply of sulphur for next year, but trust to be able to do so when I can 

 lay the result of the pluckings of the sulphured and non-sulphured areas before you." 



23rd June 1892. — '' Since the Isb June, I have been keeping a record of the pluckings 

 of sulphured and non-sulphured areas, and on a separate sheet I give you the results. 

 'You will observe that over three weeks' plucking, the average per acre is IIH) of leaf in 

 favour of the sulphur for every time the acre was plucked, or, say, 33tb in all. At first 

 sight this does not appear a very large increase, but you must remember that only the 

 worst places were sulphured, and now it is evident these sections are doing rather better 

 than the rest. Also I have refrained from comparing pluckings till red spider was fairly 

 on tbe mend; had I done so from the beginning of May the differenoe would have been too 

 maried and misleading. 



•' Leaving out of consideration all diiferences between sulphured and non-sulphured 

 areas, and taking them as of the same value, the difference in favour of the sulphured 

 would be 44ib leaf or lift tea per acre for the whole month. The cost of treatment 



' Very caveful experiment will be necessary before concluding that sulphur is actually effective against 

 mosquito blight, for the experience of entomologists in other parts of the world seems to be that while 

 sulphur is exceedingly active against all kinds of mites (of which red spider is one), it has little effect 

 on insects.— E. ('. C. 



2 " It may be noticed that washes made of soap .ind sulphur combined have been recommended both 

 in the United States and in England for use against mites like the red spider. The wash is sprayed on to 

 the plants by means of a force pump fitted with a nozzle to give a very finely divided spray. Thia 

 mettiod of applying the sulphur may possibly prove cheaper and more effectual than dusting it on to the 

 leaves, though Mr. Playfair's experiments with sulphur in powder seem so successful as to leave little to be 

 desired. Compounds of soft soap and sulphur can now be purchased in England ready made, so as only 

 to require the addition of water. In her fifteenth annual report on Injurious Insects, Miss Orraerod men- 

 tions the Chiswick Soap Co., of Chiswick, England, as a firm from which the mixture can be procured." 

 — {Extract from " Indian Museum Notes,"} 



