112 



THE TROPICAL AGRICULTURIST, 



[August i, 1883. 



and perhaps on others, almost any day, I have no power 



to deal with such cases/' 



Having had my special attention called to this matter 

 by his 'Excellency Ihe (iovernor, I availed myself of every 

 opportunity either for iin|uiry or of observation. On the 

 very limited g:rouud I was able to cover on the main 

 river, as I have said, I met with very few balata trees, 

 and no tree that had been destroyed. The creek mentioned 

 by Mr, im Thuru I asceudetl as far as the time at my 

 disposal wdidd permit, but, unfortimately, as the land was 

 everywhere Hooded, I could land in very few places. The 

 Akaiwiui is, in fact, however, a very considerable river, 

 and the whole period of my leave, could 1 have spared 

 it, might have been occupied in its exploration. Ouly its* 

 higher reaches appear to be occupied by Indians, and here 

 the balata tree is said to bt* more plentiful. So far as 

 I can ascertain, none of this gum is gathered ou the 

 Essequibo or any of its tributary rivers. A wonderful 

 impetus must have been given to the trade in Berbice 

 within the last two years. In 1881 93,578 lb. was ex}jorted, 

 or more than double the quantity of any previous year. 

 From the products of our forest which are utilised, im- 

 portant as they undoubtedly are, the colony derives hardly 

 any profit, while the forests are impoverished by wontou 

 waste and the depredations of the dishonest, and the trade 

 is in the bauds of a few merchants. As to the balata 

 trade, unless some efficient method of utilising the whole 

 of the bark be discovered, felling should be prohibited, and, 

 if, with this rule, an export tax were imposed, and every 

 package containing the gum requu-ed to bear a special 

 brand belonging to the grant on which it was gathered, 

 which would show the production of each gi-ant, a very 

 salutary change would be effected in the trade. 



As the pri\'ileges accorded to the aboriginal Indians are 

 now under review by the Government, it may be hoped 

 that the damage done by the nefarious acts of traders and 

 others, which they are enable to perpetrate by means of 

 these people, will not much longer continue; though only 

 a new and comprehensive forest law will meet the whole 

 forest question of the country. G. S. Jenmak. 



Tan as a Manuee. — Probably most persons would laugh 

 at the idea of this ; but in some instances tan has been 

 used with good effect ; and it has been used to destroy 

 the Gooseberi'y caterpillar by placing it under the bushes 

 when the larvae are issuing from the ground. Mostplatits 

 root freely into tan-beds when that material is used as a 

 medium to plunge in, and that they are benefi^tted by it 

 I am certain. I would not waste any spent tan ; after it 

 was past using as a plunging material it could be used 

 freely ou hea\y soils. J. Dooglas. 



— Gai-deners' Chronicle. 



IxsECTiciDKS. — Few plant cultivators will deny that the 

 question of insecticides for plant pests is one of great im- 

 portance, and one on wiiich there is much variety of opin- 

 ion as to the relative merits of the nuniy preparations 

 supposed to possess the power of destrnyuig the various in- 

 sects to wliich pliiuts are subject without injury to the plants 

 themselves. There exists, however, a pretty generally ludd 

 opinion that a perfect i* secticide for plants is still a de- 

 sideratimi, and therefore it is to be hoped that the inVn- 

 tion of analysing the viirious insecticides in the market 

 and opening up a discussion, out of which we m;iy gain 

 much more information than we at present possess of the 

 nature of tbp iustcts themselves, may result in the dis- 

 covery of an insecticide that, shall prove eflicacious in all 

 cases without injury to the health of the plants oi>era1ed 

 upon. Here, at Kew, where the reqiiirements of tlie estab- 

 lishment are such as to make the coUeetiun much more 

 subject to the attacks of inst-cts than in ordinary ca-cs. the 

 necessity of keeping so many totally different plants grow- 

 ing together— different in many cases both as regards the 

 temperature, moisture, and light reqnire<l — we are sorely 

 tried in our efforts to keep the pests under. As in the 

 case of animals so it is with plants, ill-health generally being 

 the signal for the visitation of vermin, and where plants 

 are crowded together under such unfavourable conditions 

 as those I have mentioned the growth and increase of in- 

 sect pests is often simply alarming. It is only by con- 

 tinual sponging, syiiuging, dipping and other such Fmeans 



that we can hope to keep the plants anything like clean, 

 and there is no establishment where the discovery of some 

 easy means of lotal erailication of all plmt vermin would 

 prove a greater boon than in the botanical garden. "We 

 have ti-ied so myny insecticides, and on so many different 

 subjects, that I venture to offer a few remarks on one or 

 two of them, and as much importance seems to be attached 

 to the useful qualities said to be possessed by tiie Pyre- 

 thrum powder perhaps what I know of it as an insecti- 

 cide may be worth recordiug. A box of beetle powder, 

 which is, I suppose [On what grounds ?], nothinL' but 

 Pyrethrura powder, was got for experiment, and used as 

 directed for various plants and ou various inst^cts, Im- 

 pritiens JSuItaui before jt flowered was sorely infested by 

 ants which, in addition to sapping the life out of the 

 young leare.s, exercised themselves by establishing a colony 

 of bugs ail over the plant. We washed off tdl the bug, 

 atid then submerged the whole plant in a tank of water, 

 where it remained for two hours. This drove out all the 

 ants from the soil. After tlie plant was dry we dusted it 

 all over with the powder, aiul placed a ridge of the powder 

 all round the stem of the plant. It was of no use ; the 

 ants were as busy as ever in a day, and carried their 

 loads over the ''poisonous" jiowder without showing the 

 slightest alarm. "We also dusted Abutilons infested with 

 red-spider. Pelargoniums infested with greenfly, and some 

 Crinums with thrips, as well as various other plants on 

 which sc^le and bug were at home. " AYe might as well 

 have thrown sugar at them ; perhaps better, for this stuff 

 may hurt the plants." So said the man who assisted me. 

 For horticultural pm*poses the beetle powder proved with 

 me to be perfectly useless. It may be that Professor 

 Riley's experiments were made with a much more powerful 

 preparation than that I used, but so little was the effect 

 tliis powder had on t e insects it came in contact with 

 that 1 am inclined to doubt tiie iusecticidal powers of 

 Pyrethrum ]iowder in any form. An insecticide of which 

 I iiave ht'ard much both for and against was tried here 

 some two years ago. [We omit the uame till analysis has 

 been made.] In this case the vendor himself prepared the 

 mixture and dipped the plants selected : a good-sized Palm 

 some small ones troubled with hag at the root, some Bam- 

 busas on which red-spider was in atrong force, and several 

 Ferns infested with scale were tried. The Palms were 

 submerged, root and all, as t'le niixiure was said to be 

 not only a first-rate insecticide but a good ferti]iseraJ>o ! 

 The gentleman called about a fortnight after the dipping 

 operation and saw for himself, the Palms quite dead, the 

 Bamboos much injured, and the Ferns curled up like 

 scorched Bracken, while the insects seenied to be no fewer 

 nor yet even more sick tiian before the o eratiou. Since 

 t' en I 1 avft heard the opinion of others as to tlie'merits 

 of the liquid, and it is only fair to say that in some 

 cases the verdict was as favourable as mine was unfavom-- 

 able. Fowler's insec'icide, Gishurst Compound, and other 

 insecticides are only useful in those cases where tobacco 

 fumigation is not convenient, as aphides, red-spider and 

 thrips seem to be tiie only insects that f.^ll victims to 

 them. Parafiin is an effective yet a daugerous inst-cticide 

 to use for plant pests. Bad oi), carelessness in applvin-^ 

 the mixture, or the injurious effect paraffin, however 

 much diluted, has on many plants, make the use of th:s 

 insect destroyer not always safe. Here at Kew, however 

 a great deal of parafhn is used, Palms, Cycads, and many 

 hard-lfcitved dicotyledonous plants proving capable of stand- 

 ing a dose of diluted paraffin without showing any ill 

 effect, Soft-soap and tobncco-water are generally mixed 

 iilong with the paraffin. "We want something that will 

 destioy bugs, scale, and those other hard-to-kill insects 

 without injury to any plant howtner delicate it may be 

 — something one may syringe down into the lieart of a 

 bulbous plant, antl d< stroy thi- bugs nesting there with- 

 out destroying or seriously itijuring the bulbs as paraffin 

 docs — a mixture one may use for Ferns, young Cycad leaves 

 Orchid, kc, without having pounds worth of loss as the 

 result of its use. if Pyrethrum will do it then tlie ques- 

 tion of its cultivation Ui quantity can soon be solved ■ 

 but wliatever the d(^sideratuin m;iy discover itself as, the 

 f;r<at ser^iee .such an insecticide would be io horticultur- 

 ists may be seen ill the mary inquiries for in.selicide.s, and 

 the tliDusands of pounds wortli of stuff's .sold as .-^uch. 

 W. Watson, Kew. — Gardeners* Chronick. 



