AOL. XII. No. 281. 



THE AGUICULTURAL NEWS. 



43 



Station. A yellow weevil, found attacking the leaves of 

 liuie trees, was responsible for some small amount of damage 

 at various points; the insect itself is new to me. 



In Virgin Gorda sweet potatoes had been very badly 

 damaged by the ordinary sweet potato hawk moth (Proto- 

 parce ciinjxdata); while at the Experiment Station some 

 damage had been done to arrowroot by the arrowroot worm 

 {Calpodes et/tlius). 



The Jack Spaniards mentioned above are probably 

 Polistes sp., perhaps P. fuscatuH-mslabilis, which 

 occurs commonly in the Leeward Islands, but probably 

 not the same species as P. anvularis, which is so 

 valuable as a natural enemy of the cotton worm in 

 St. Vincent and Barbados. The scale insects of limes 

 mentioned are the purple scale {Lepidosaplies heckii) 

 [Mytilaspis citricola], the green scale {Coccus viridis) 

 [Lecanium viride], and the white scale, Chionaspis 

 citri. 



The yellow weevil, mentioned as attacking the 

 leaves of lime trees, is a species of Diaprepes quite 

 different from the root borer (D. abbreviatus) of sugar- 

 cane in Barbados, resembling /). spengleri but appar- 

 ently being distinct from it. The grub of D. spengleri 

 is reported to attack roots of orange and other citrus 

 trees in Porto Rico, and it also occurs in St. Vincent, 

 where, however, the habits of the grub do not seem to 

 be known. 



Agricultural Development in the United 

 Kingdom. — Speaking at the annual dinner of the Farmers' 

 Club on Tuesday, December 10, ilr. Runciman, President of 

 the Board of Agriculture and Fisheries, referred to the 

 assistance which the Development Commissioners propose to 

 give to agricultural research. In the course of his remarks, 

 he said: It was not enough merely to adopt a policy of 

 slaughter, scheduling areas, and so forth. They should adopt 

 so far as possible all the services that science could supply. 

 They must give their research institutions, universities, and 

 colleges the needful to ascertain more and more the nature of 

 their most dangerous diseases. He had received permission 

 only that day to announce that one of the schemes he had 

 been enjoining for some months in the country had so far met 

 with the approval of the Development Commissioners that 

 they would shortly recommend to the Treasury a release from 

 the Development Fund of moneys for the following objects: 

 First of all to provide in every one of what were now called 

 the provinces, for the purposes of agricultural education, the 

 services at the headquarters of those provinces of men 

 concerned with advice as to soils, crops, and so forth, but who 

 should be concerned also with live stock; that each one of 

 these men should be an organizer or supervisor, to organize in 

 that province a live stock scheme which would be described in 

 further detail. The Commissioners were also prepared to 

 enable them, with an annual sum, to have engaged in their 

 office a man of the highest class, who could not know 

 everything about every branch of live stock, but, by general 

 knowledge, would be able to give administrators advice, which 

 at present they were without. Thirdly, premiums would be 

 provided from the Development Funds for the breeding of 

 heavy horses, Shires, Clydesdales, Suffolk Punches. (From 

 Nature, December 12, 1912.) 



EFFECT OF TAPPING UPON THE COMPO- 

 SITION OF RUBBER. 



Recently, samples of rubber prepared by different 

 methods, by the Ceylon Agricultural Department have 

 been sent to the Imperial In.stitute for examination, 

 and the present article is based upon an account of this 

 examination which appears in the Bulletin oj the Imperial 

 Institute, Vol. X, No. 3. 



The tapping of the trees was performed (1) by the 

 knife only (excision), (2) by the pricker only (incision), and 

 (3) by a combined method. u.sing both knife and pricker. 



In the first series of experiments, the first specimen 

 consisted of Para crepe obtained by the use of the knife only, 

 V and half-spiral cuts being made. This rubber was light- 

 brown in colour and exhibited good elasticity and tenacity. 

 It contained 94 per cent, of caoutchouc and a relatively 

 low percentage of ash. It was valued in London at 4s Qd. 

 per tt) , with fine hard Para at 4s. Zd per lb. 



The second sample was Para crepe obtained by V and 

 half-spiral cuts with Bowman-Northwaj' knife and pricker. 

 This was thin crSpe rubber varying in colour from light to 

 dark-brown. The rubber exhibited very good elasticity and 

 tenacity. It contained 94 per cent, of caoutchouc and 

 a relativel)' high percentage of ash. It was valued at the 

 same price as the first sample. 



The third was Para crepe obtained by vertical cuts and 

 Kelway Bamber's pricker. This was dark-brown, thin, crepe 

 rubber, which was apparently not quite as strong as the two 

 preceding specimens. 



All the samples, especially No. 3 prepared by making 

 vertical cuts, were rather dark in colour for plantation crepe. 



Specimen No. 4 of the second series consisted of rubber 

 biscuits from trees tapped with the knife only. These were 

 thin, light-coloured biscuits, clean and well prepared, but 

 showing white surface marks. The elasticity and tenacity 

 of the rubber were very good. It contained 91 '6 per cent, 

 of caoutchouc, and the amounts of resin, protein and ash 

 were somewhat high. 



Sample No. .5 consisted of rubber biscuits from trees 

 tapped with Bamber's pricker: thin light-brown biscuits, clean 

 and well prepared; a few of the biscuits showed white surface 

 marks. The physical properties of the rubber were very 

 satisfactory. As regards composition this sample contained 

 92'1 per cent, of caoutchouc with rather high percentages of 

 resin, protein and ash, though the loss on washing was con- 

 siderably lower than in the case of sample No. 4. 



These two samples were valued at about 4s. lid. per ft. 

 in London, with fine hard Para at 4s. 8d per lb. 



Following on the above information in the account 

 already referred to, is a description of a chemical exami- 

 nation of rubber from Manihot dicJwtonm. This has 

 been said to be superior to M. Glaziovii, the well- 

 known Ceara rubber tree, as a source of commercial 

 rubber. Recently, some trees of M. dichotoma were tapped 

 for the first time. The sample sent to the Imperial 

 Institute consisted of four pieces of dark-brown, thick 

 crepe rubber. Two of the pieces exhibited fairly good 

 physical properties, but the other two were soft, sticky, and 

 very weak. Rubber represented by the two best pieces of 

 this sample would probably realize about if. per Di. in 

 London, with fine hard Para at 4s. M. per ft). The rubber 

 contained 84'6 per cent, of caoutchouc, and the percentages 

 of resin, protein and ash were relatively high. 



It is believed that this rubber was obtained from very 

 young trees, and that the product may improve as the trees 

 increase in age. 



