PART 1V. ) 
MEASURES OTHER THAN HAND-PICKING FOUND PRACTICAL FOR THE CONTROL 
oF Antestia oN COFFEE. 
Mr. RITCHIE said that in Tanganyika a poisoned syrup had 
been used since 1923. This was Zimmermann’s formula. Now 
practically every planter in the Kilimanjaro and Meru areas had used 
the syrup with satisfactory results. The only damage done had been 
due to careless application or lack of supervision. Further details 
were to be found in the Tanganyika Report for 1924-25. 
Mr. TRENCH had carried out experiments on spraying, using the 
following mixture : — 
4 oz. Arsenite of Soda. 
2 lbs. Jaggery. 
4 gallons of water. 
This is sprayed over the bush in the form of a mist, and the 
planters who had used this had had satisfactory results. 
Mr. RITCHIE had had no good results with Arsenate of Lead, 
the Mally formula, but good results with Arsenite of Soda. 
The CHAIRMAN (Mr. Fuller) thought that it was possible that 
the Arsenate of Lead had been precipitated on the leaf and not taken 
up by insects. 
Mr. FULLER asked Mr. Trench what effect the spraying had on 
the finished coffee product; he instanced the case of the Union where 
the spraying with Arsenate of Lead had affected the flavour acid 
content of the fruit. It took three seasons before the bad effect had 
worn off. It was also found that by the use of the Mally bait the 
flavour of the fruits of apple, pear and plum were impaired, and it 
would be of interest to know whether coffee reacts in the same way. 
Mr. HARGREAVES said that experiments in Uganda had shown 
that by using Mr. Trench’s formula the scorching and burning of the 
foliage was serious. A method of applying the bait had to be found 
so that the poison did not come into contact with the plant. Strips 
of hessian cloth weére soaked in the poison and placed where the 
insects could get at them, but this method had proved ineffective. 
Mr. TRENCH said that as far as he was aware, spraying with 
Arsenite of Soda had so far had no deleterious effect on the finished 
coffee product. 
Mr. RITCHIE, in reply to Mr. Hargreaves, stated that the 
spraying had been effective at 3,000-5,000 feet on Kilamanjaro, and 
4,500-5,000 feet in Arusha. It was apparent that humidity and 
temperature had to be taken into account. 
Mr. FULLER pointed out in this connection that the results 
seemed to depend on what Arsenite was used. 
Mr. HARGREAVES said that for the earlier experiments the 
Arsenite was obtained locally; afterwards the Arsenite was made by 
the Government Chemist from white Arsenic and Soda. and still 
scorching resulted. 
~ The CHAIRMAN (Mr. Fuller) stated that experiments were 
being conducted in South Africa with the Mally remedy for adult 
moths, and seemed promising. 
19¢