439 



bv immediate or early threshing. Unthreshed grain in storage 

 furnishes ideal conditions of heat and moisture for this pest, which 

 may produce annually as many as eight generations. 



Treherne (R. C). The Control of Insects in Ships by Steam. — 



Agric. Gaz. Canada, Ottawa, v. no. 7, July 1918, pp. 668- 

 669. 



The case is cited of a small coasting steam-vessel conveying a cargo 

 of rice from Seattle to Vancouver, which on arrival was found to be 

 heavily infested with Calandra oryzae (rice weevil). As it was desired 

 to reload with a cargo of flour, it was necessary to disinfect the hold, 

 where enormous numbers of the weevil were still present. Accordingly 

 an all-night sulphur fumigation was undertaken, 20 lb. sulphur being 

 burned in an iron carrier in the hold, which was 43 ft. long, 18 ft. wide 

 and 8 ft. deep. Next day, after opening and airing the hold it was 

 found that only part of the weevils had l)een destroyed, and a further 

 treatment with superheated steam was decided upon. One of the 

 steam pipes was accordingly disconnected and turned inwards, the 

 hold was battened down and the upper deck was washed down with 

 boiling water. On examination of the vessel after 5 hours of this 

 treatment, with a temperature of 200° F. within the hold, no living 

 weevils were visible, but 12 hours later the weevils began to reappear 

 from the bilges whither they had retreated and to which the heat 

 had not penetrated. A third attempt was therefore made, the bilges 

 being flooded and the hold superheated as before ; the result was 

 eminently satisfactory, all trace of weevil infestation being destroyed. 



Before the method can be recommended for a cargo-laden hold, 

 a fuller knowledge of the effects of wet and dry heat on dried stored 

 products and grain is necessary. As regards rice, at any rate, the 

 treatment with heat is a dangerous practice, since superheated rice 

 becomes useless for milling. 



Jack (R. W.). Notes on Remedies for Turnip Sawfly [Atlialia 

 jiacca, Konow). — Rhodesia Agric. JL, Salisbury, xv, no. 3, 

 p. 279. 



The earlier experiments with arsenical compounds in the form of 

 dust against Athalia Jiacca were made during the wet season, when the 

 pest is most injurious, and failed, owing to the applications being 

 immediately washed away. 



During the wet season of 1917-18, A. Jiacca was very prevalent in 

 Southern Rhodesia, and was recorded for the first time at Salisbury. 

 It continued its ravages after the cessation of the rains, which allowed 

 of the application — ^by means of stilphur bellows — of a dry mixture 

 consisting of Paris green 1 lb. and slaked hme 20 lb. ; sixteen hours 

 later, large numbers of the insect were found dead on the ground, 

 showing that the treatment can be recommended as highly effective, 

 if an interval of this duration without rain elapses after the 

 application. The mixture is, moreover, cheaper than parafi&n 

 emulsion, is not in any way injurious to the plants, and is more 

 eft'ective on the larger ones. 



