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Plant Sanitation. 396 [Nov. 190(5. 



There is another possible cultural method that is now being made the 

 subject of experiment. It has been suggested that dense shade, by inducing a more 

 sappy growth, may render the plant unsuited for the propagation of the insect. 

 The partial, checkered shade offered by Grevillea and Albizzia, as usually cultivated, 

 is evidently non-deterrent. I propose to try the effect of a dense shade of some 

 fast growing tree which can be readily removed or thinned out when it has served 

 its purpose. The common ' dadap ' (Erythrina lithosjierma) commends itself as 

 particularly suitable for this experiment. If this treatment proves successful it 

 may be possible to exterminate the borer, in any particular field, by leaving it 

 under shade for a year, then thinning out the shade and pruning the tea. Such 

 treatment will necessarily result in some dimunition of the crop for the period 

 during which the tea is under treatment, but if the desired end is attained, the 

 temporary sacrifice will be warranted. 



A correspondent has sent me detailed accounts of a treatment by which 

 he reports that the beetles can be killed in the living stem. His method, as given 

 in his own words, is as follows :— " For the destruction of the pest, scorch the 

 bushes behind the pruners with torches made of coconut leaves. A few grevillea 

 leaves or other rubbish lying about may be placed in the centre of the bush to 

 help the flame. The torch is applied below to the centre and moved round the 

 bush towards all the side branches— the insect will be found dead on its back in the 

 cell. The white grubs (young beetles) are also killed. The cost of firing, with 

 women and boys, is not more than Rs. 13 per acre, including torches. A cooly does 

 260 bushes in damp weather and 250 in fine weather," 



I know, from experience, that a comparatively short exposure to heat is 

 sufficient to kill the insects. Also that a tea bush rapidly recovers from the effects 

 of fire. But there is one point that must be carefully determined before this 

 treatment can be recommended. Will, as is very possible, the semi-scorched 

 branches be rendered specially attractive to the beetles and so result in rapid 

 reinfection? 



In the above details of the experiment the cost may be considered very 

 high, if not prohibitive. But I am informed that Rs. 8 of the quoted figure is 

 expended in the torches alone. It is probable that some more economic form of 

 torch may be devised. An absorbent material soaked in kerosene could be employed. 



THE EGYPTIAN COTTON WORM. 

 a natural and economic method for prevention. 

 By Walter Draper, p.l.s. 



The serious loss to the Egyptian cotton crop, caused by the attack of insect 

 pests, and the enormous area under this valuable summer product, render the 

 subject of pest extermination sufficiently important to claim the attention of all 

 cotton growers. Information of the metamorphosis of the cotton worm has been 

 given from time to time by the Ministry of the Inferior through the Press, so that 

 its various stages of egg, worm, chrysalis, and moth should be familiar to all. 



It is well known to botanical authorities responsible for the healthy 

 maintenance of a large collection of plants that the checking of insect pests forms 

 an important item in their successful management. In Egypt, where huge areas 

 of a few kinds of plants— not indigenous to the country— are annually grown agri- 

 culturally, natural enemies are at times bound to occur. 



The success of hand picking eggs and worms from infected areas has been 

 fully demonstrated and proved, and, in a European country, this work could be 

 carried out with comparatively little assistance ; but in Egypt, the tardiness of 

 the native cultivator to clean and keep clean his crops is a great obstacle to the 



