Dec. 1906.] 



493 



Plant Sanitation, 



and wing cases) blackish. Each gallery was found to contain a single female aiid 

 many larvae in different stages of development. No males were observed. The 

 infected tissues still smelt strongly of camphor, showing that this substance causes 

 no inconvenience to the insects. It is fortunate that our system of cultivation 

 provides an efficient check to the increase of the pest. Our camphor is distilled 

 from the leaves and young branches of the plant. All affected branches (the marked 

 discolouration of the bark makes their recognition easy) should be cut out and 

 passed through the still as soon as possible. It is probable that the beetle is breeding 

 in some allied jungle tree. The ' Kudu-da wulu ' (Liisea zeylanica) and the various 

 wild cinnamons may prove to be the natural host plants. 



The caterpillars of a common moth (Prodenia littoralis) have been sent in 

 by a tobacco grower. They are said to eat large holes in some of the best leaves. 

 Hand picking is the only practical remedy in such cases. At the first appearance 

 of a hole in the leaf, the plant should be thoroughly searched and the depredator 

 will usually be discovered sheltering beneath one of the leaves. During the heat 

 of the day they retire to shadier parts of the plant. 



Gourds, cucumbers and vegetable marrows are often spoiled by the presence 

 of maggots in the fruits. These are the larvae of the 'Cucumber Fly' (Dacus sp. 

 which lays its eggs in the young fruits. The only satisfactory method of dealing 

 with the pest is to cover the fruit— immediately after it has set — with muslin bags 

 large enough to contain the mature fruit. This would be difficult with some of the 

 larger gourds ; but in such cases the bag might be removed when the fruit is only 

 partly grown, as by that time the rind has become fairly thick and will be able 

 to repel the attacks of the fly. All infested gourds and cucumbers (recognizable 

 by the exudation of a gummy matter) should be at once collected and 

 destroyed. If allowed to rot on the ground, the flies will mature and give 

 further trouble. 



Small grasshoppers are reported to have given trouble in some nurseries of Para 

 rubber, by nipping off the young seedlings. Injury of this kind could be prevented 

 by dusting the young plants with a mixture of one part Paris Green to six 

 parts lime. 



An up-country correspondent has written complaining of annoyance from 

 mosquitoes in the bungalow, and asking for advice in their eradication. The only 

 way to be free of mosquitoes is to get rid of their breeding places. This should 

 not be difficult in the hill districts, where there is little or no stagnant water. 



Probable breeding places are :— 



1. Tubs and tanks for catchment of rainwater. 



2. Discarded chatties, pails and tin cans. 



3. The hollow stumps of bamboos, in bamboo clumps. 



4. The flowers of the 'Lobster-claw' plant (Heliconia.) 



Tubs and tanks should either be made mosquito-proof by means of close-fitting 

 covers, or treated periodically (once a week) with kerosene. A brush of rags on a 

 stick, dipped into the oil and stirred into the tank, will produce an effective surface 

 film and kill any mosquito larvae that may happen to be in the water. If the water is 

 drawn off by means of a tap below the surface, no taint of kerosene will be 

 observed. 



Old chatties can be broken. Discarded pails and empty tins should 

 be buried. The bamboo stumps should be plugged with clay or lumps of turf. 

 ' Lobster-claw (Heliconia brasiliensis) is a favourite shrubbery plant and produces 

 its blossoms in handsome scarlet concave bracts which retain considerable quantities 



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