543 



A series of experiments near the laboratories of the department are 

 in progress to estimate the cost ol eradicating lalang by the following 

 processes : 



1. Spraying and arsenite of soda ; 



2. Digging and picking out all roots ; 



3. ,, re-chungkoling ; 



4. The introduction of Passiflora fcetida, " wild passion 

 flower," a vigorous creeping plant which smothers lalang 

 and can itself be easily removed. 



These are being carried out in various ways on some 10 1-acre lots 

 and the exact cost in each case recorded. The lalang, which has been 

 in possession of the fields for some years, is tall and vigorous, typical 

 of thousands of acres which are to be found throughout the Peninsula. 



Health of Rubber Trees. 



The health of rubber trees has remained good during the year, on 

 new disease has to be chronicled, and the diseases which were already 

 known have shown no special activity. Both the root fungus (Fomes 

 semitostus) and the rubber termite (Termes gestroi) have done a large 

 amount of damage. The Government Entomologist carried on a 

 most successful investigation into the life history of the rubber termite, 

 discovering many details of its methods of attack, a knowledge of 

 which will enable the planter to carry on a much more successful 

 campaign in the future. It is much to be hoped, considering the 

 immense monetary loss caused by this ubiquitous pest, that these 

 investigations will soon be continued and completed. The interim 

 report which he has published shows among other interesting facts 

 that the planters' methods of only dealing with the white ants when 

 he finds them on a rubber tree are not the most strategical measures of 

 attack. The rubber termite is found in large quantities in decaying 

 stumps, and it is in these places that they can be destroyed in large 

 numbers, whereas there are ants differing very slightly in appearance 

 which are found on rubber trees which do no damage to the living 

 rubber tree. 



The nests and their characteristic connecting tunnels are clearly 

 described by Mr. Pratt, and the planter is thus enabled with more 

 definite knowledge to carry on the war against this most insidious and 

 ever-present menace to healthy rubber. 



In addition to this valuable piece of work, the Government Ento- 

 mologist investigated and reported on an attack by a longicorn beetle 

 on rubber, a stinging caterpillar (Thosea sp.) on cocoanuts, and made 

 an examination of some padi insects which he was unable to follow up 

 so as to gain definite knowledge as to the life histories and 

 methods of attact of these pests. 



The Government Mycologist has visited various estates and given 

 advice as to the prevention and cure of various diseases of cultivated 

 plants. 



Rubber Machines. 



The number of estates which have trees of sufficient growth for 

 tapping is as yet not very many, but each year more become productive, 

 and the question of the best and most economical machinery for pre- 



