Miscellaneous. 



222 



[March 1908. 



three months to investigation of the life 

 history of the insect, and more especially 

 to the effect of various insecticides upon 

 it at different stages of its growth. 



The high cost of kerosine emulsion led 

 to the conclusion that our first efforts 

 should be directed towards the discovery 

 of a cheaper and not less efficacious in- 

 secticide. After long and patient experi- 

 ment, Mr. Antram has been successful in 

 finding a solutiou which is equally as 

 deadly in its action on the insect as 

 kerosine emulsion, and at the same time 

 can be applied at twice the rate per acre 

 at one quarter the cost of the latter. 

 The immediate object of this report is to 

 make known the composition of this 

 solution in time to allow of its use 

 during the present cold weather after 

 pruning. 



The composition of the soap solution 

 for mosquito blight is as follows : — 

 " Primrose " soap 1 lb. ; water 20 gallons. 

 Primrose soap is an ordinary yellow bar 

 soap, easily procurable in this country. 

 It has been selected on account not only 

 of its superior insecticidal effect, but for 

 its property of forming a clean solution 

 which will readily pass through the fine 

 vermoral nozzle of the sprayer, other 

 makes of soap having a tendency to form 



gritty deposits which choke the nozzle. 

 The simplicicity of the solution should 

 make it easier to prepare and use than 

 kerosine emulsion, nor has the soap 

 solution any tendency to burn the 

 bushes. 



The solution should be applied at the 

 rate of 300 gallons per acre for each round 

 of spraying, the cost of which application 

 will be about Rs. 2-8 per acre, as com- 

 pared with Rs. 6 per acre required for 

 applying 150 gallons of kerosine emulsion. 

 — Statesman, 21st Feb., 1908. 



[Note by Mr. E. E. Green, Government 

 Entomologist : — 



Spraying is only useful on completely 

 isolated fields or where the whole area 

 is pruned down at one time — as in India. 

 In Ceylon, where the custom is to cut 

 down one field at _ a time, any such 

 remedial treatment is quickly negatived 

 by invasion from surrounding fields. 

 Recent experiments at Woburn have 

 shewn that the best and most perfect 

 emulsions are made without soap at all, 

 but using a Bordeaux mixture made 

 with clear lime water as the emulsifyer 

 and a heavy oil (bulk oil) instead of 

 kerosene.— See 8th Report, p. 24, 

 et seg.] 



