Plant Sanitation. 



St 



eggs, as it is clear that, on the first invasion, there would be no larval galleries 

 in which to oviposit. It is possible that the fibrous matter at the base of the 

 young fronds may form a nidus for the eggs. Pal my rah palms suffer equally with 

 the coconut. There are many stunted palmyrahs in the neighbouring scrub, and 

 these are thickly infested by the caterpillars. Such useless palms should be 

 destroyed as they will harbour the pest after it has been eradicated from the 

 coconut estates. It is intended to issue a circular given the fullest particulars 

 about this pest and the best means of combating it. 



The Red Weevil and Black Beetle may be considered together as, in Ceylon, 

 they appea'rHbo be very largely interdependent upon each other. There seem to 

 be good grounds for believing that the reduction of the Black Coconut Beetle 

 results in a corresponding diminution in the numbers of the Red Weevil. The 

 smell of the fermenting sap that exudes from the holes excavated by the former 

 attracts the latter and affords an easy entrance for it. On the other hand, the 

 decayed stems of palms that have been killed by the Red Weevil form a favourite 

 breeding place for the Black Beetle. The importance of the destruction of such 

 breeding places is not sufficiently realized. Cases have occurred where the estates 

 have been fenced with dead palm stems within which the beetles were breeding 

 in thousands. It will be necessary when the Pest Ordinance comes into force, to 

 insist upon the destruction (preferably by fire) of all dead palms and decaying 

 rubbish. 



To the south of Batticaloa several abandoned coconut estates were observed, 

 upon which hundreds of dead palm stems are left standing. The remaining trees 

 are dying fast, probably being killed out by beetle (see Plate B). The dead stems 

 must be breeding enormous numbers of the beetles. Government should be 

 petitioned to take over these places — under the Waste Land Ordinance— and put 

 them into a sanitary condition. At present they are a standing meuace to the 

 neighbouring estates. 



Of the two species of scale bugs (Coccidae) frequenting the Coconut Palm 

 the 'scurfy scale' {Aspidiotus destructor) is the more serious. It occurs in large 

 colonies covering the undersurface of the fronds. Such fronds may be recognized 

 by their sickly yellow colour, and should be cut off and destroyed. This species 

 is reported to be extremely destructive to Coconut Palms in the Laccadive Islands. 

 The other species {Hernichionaspis minor) is of little importance and is unlikely 

 to cause any aiipreciable injury. 



Mosquitoes are a serious inconvenience in the Batticaloa district. I have 

 never encountered Anopheles mosquitoes in such enormous numbers as during my 

 two visits to Batticaloa. Each morning the outside of my mosquito net was 

 thickly sprinkled with disappointed applicants for my blood. Anopheles rossi was 

 the principal species, and is probably responsible for the occasional outbreaks of 

 malarial fever. In Batticaloa town itself, the sole breeding place appears to be 

 the margins of the brackish lake. Any remedial measures will be very difficult 

 in such situations. On the estates I found the larvae abundant in the small water 

 holes scattered throughout the properties and used for watering the youug 

 coconut plants. On some estates earthenware chatties are sunk at the base of the 

 youug palms and frequently replenished with water. These also afford breeding 

 places for various mosquitoes. The destruction of the larvae in the water holes 

 and chatties would be comparatively simple. A bunch of rags, fastened on a stick, 

 should be soaked in kerosene and stirred into the lioles, leaving the merest film 

 of oil on the surface. This should be repeated at intervals of three or four days. 

 The small amount of oil on the water would have no prejudicial effect upon the 

 plants to which it was applied. 



