410 



THE AGRICULTURAL NEWS. 



December 17, 1904. 



INSECT NOTES. 



St. Vincent. 

 The following are extracts from Mr. })allr>u"s 

 report on his recent visit to St. Vincent : — 



BOTANIC STATION. 



A careful inspection of the nurseries and gardens at the 

 i>otanic Station wa.s made and they were found to be in 

 excellent condition. Several of the more common .scale 

 in.sects were seen, but with very few exceptions the.se were 

 in small numbers and not causing any appreciable injury. 



The Liberian coffee trees, mentioned in my last report, 

 are much improved, though there are a few live scales still 

 to be seen on them, and the cinnamon trees also are very 

 much improved, though a few live scales {Protopulvinaria 

 ■jii/yiformis) are still to be seen. The fiddle wood trees 

 {Cilhnrexijlwn fjiiadraii'pifare) were attacked by a Aveb worm. 

 TJiis insect could jirobably be best controlled by spraying 

 with arsenate of lead, or the trees might be removed 

 altogether except o/te .specimen for the species. 



Oranges do not thrive in the Botanic Station ; a few 

 Rliecimens are to be seen, but they have niade very poor 

 growth, and it would seem that the conditions are not right 

 for them. A few live scales were to be found on each of 

 them, and on a few many dead ones. 



There were a number of trees on which black blight 

 (C'lpnocb'ini) .sp.) was to be seen, but the scale insects do not 

 •seem to do much harm. The mango trees and the Indian 

 teak seemed to be most aflFected, especially the row of teaks at 

 the u])per entrance io the gardens. These are outside, but 

 possibly an arrangement might be made to have them lopped 

 and sprayed by the labourers from the garden. 



There were but few plants in tlie nurseries at the time 

 of my visit. Of these by far tlic greater number were 

 cacao seedlings and they appeared to be healthy and free 

 from scale or other insect pests. A few Bois Immortel 

 plants were infested with white scale {Biii!']>is ami/gdah'). 

 These were to be taken out and destroyed. 



Ar.RICl'LTUKAL SCHOOL. 



The cotton at the Agricultural School had made excel- 

 lent growth. It was slightly attacked by the leaf-blister mite 

 iind a few cotton stainers were to be seen. A field of corn was 

 badly attacked by the moth borer of the cane {Diatraea 

 sanharalis) and the corn ear worm (? I/eliolliis armigera). 

 This latter is probably the same insect that in years past has 

 done much damage to cotton in the United States by boring 

 into the cotton bolls, from which habit it has received the 

 common name of 'cotton boll worm.' The corn ear worm was 

 found only in the ear.s of the corn, but the moth borer of the 

 cane was found in the stalk and the car. The corn, when its 

 condition was discovered, was at once cut and will be fed 

 out as fast as possible. The yams in the plots above the 

 school building had been attacked, and nearly all the leaves 

 of some Tarieties were eaten. This was probably the work 

 of the slug ( »ro«?V''//f( occidfntalin), ai^ no insects could be 

 found and many slugs were hidden in the .soil under the 

 vines. This is said to be the season of greatest abundance 

 of the.se animals. Pari.s green and lime dusted on the leaves 



would probably be an efficient remedy. Tlie hedges and 

 ornamental plants were found to be in good condition, also 

 tlie cacao. 



On Thursday, November 17, I gave a lecture to the- 

 boys at the agricultural school on insects and ways of 

 combating them. It seemed necessary to make this lecture 

 an elementary talk on account of the junior boys, some of 

 whom had just been admitted to the school. 



SUPPORTS FOR VANILLA. 



Messrs. Schiinmel & Co.'s Semi-dmiual Report 

 has the following note on the above subject : — • 



De Cordemoy reports in the Journal d' Agriculture 

 Topicale (Vol. I, 1904, p. 101) on the experiences of the- 

 Reunion vanilla planters with regard to the supi>orts used 

 for training the vanilla plant. According to the author, 

 wooden or metal poles have been entirely discarded there, 

 and in the course of time the pilanters have adopted the use 

 of trees as natural supports for the vanilla. The kinds which 

 come esi)ecially under consideration are Casuarina equiseti- 

 folia Forts., called ' filao,' and further physic-nut {Jatropha 

 Curcas) and the screw pine {Pandanus utilis). The 'filao' 

 soon came out of use, as during the growth its bark peeled 

 off, and the vanilla .shoots lost their support. The experience 

 with the Jatropha was favourable, but in the case of heavy 

 shoots it was found too feeble and had to be sujiported by 

 poles. The most satisfactory was the Pandanus, which 

 through its numerous adventitious roots offers a sufficient 

 resistance to the cyclones -which occur so freijuently in 

 Reunion. It is usual to jilant the vanilla cuttings close to 

 the roots of a Pandanus, when the shoots very rai)idly twine 

 themselves round the roots and trunk. This method ajipears 

 to be the one generally employed. Very remarkable is the 

 oocurrencc of a microscopic fungus between the aerial root 

 and bark of the living support, whose mycelial filaments 

 penetrate not only the root-bark of the vanilla, but also the 

 bark of the supporting tree, and, according to de Cordemoy, 

 are important for the nutrition of the vanilla plant. 



CITRONELLA GRASS IN CEYLON. 



In a letter to the editor of the Tropical Agri- 

 cidfurint, dated (October 1, commenting on the late 

 Mr. C. J. Sawer"s article in the Chemist and Druggist 

 on ' C'itronella and Lemon Grass in Ceylon, India, and 

 the West Indies.' Dr. John C. Willis, Director of the 

 Royal Botanic Gardens in Ceylon, makes the following 

 observations with reference to citronella errass ■ — 



There are two cultivated forms in Ceylon, called ' Lena 

 Batu' and ' Maha Pangiri ' respectively. A good account 

 of them is given in Messrs. Schimmel it Co.'s Semi-annual 

 Beport for October 1898. 'Lena Batu' is the form culti- 

 vated by the native growers, and furnishes practically all 

 the exported oil. 'Maha Pangiri ' is the form cultivated by 

 Messrs. Winter it Son at Baddegama, and gives a much 

 finer oil, but needs more trouble in cultivation, having to be 

 frequently replanted. The native prefers the ' Lena Batu,' 

 because he does not need to replant it. He frequently 

 abandons the cultivation when the gra.ss is ten years old or 

 more. The wiUl Andropogon Nardua, one of our most 

 common grasses, is known to the Singhalese as ' Mana,' and 

 is distinct from the cultivated forms ; it yields a good oil, 

 but the quantity is smaller. Lemon gnvss is also cultivated 

 in Ceylon, and we have a considerable quantity of it at 

 the Experiment Station at Feradeniya. 



