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immune from the attacks of insects by the normal consumption 

 of oxygen and production of CO.,. The rate of oxygen consumption 

 and COo production varies greatly with conditions of temperature 

 and moisture, and it is difficult to determine even approximately 

 the number of insects that may be present in the wheat. While no 

 definite statement can be made, it is considered that infested grain 

 put into air-tight storage cannot be seriously damaged by insects ; for 

 if only a few were present, they could not do much damage in the time 

 before they died, and if many were present, they would all be killed 

 in a very short time by oxygen consumption and CO., production. 



A series of experiments to determine the effect of sealing 100 grains 

 of weevil-infested wheat in varying amounts of air-space demonstrates 

 clearly the efficiency of hermetical seahng even when a relatively large 

 air-space is present. The tests also indicated that seahng wheat 

 for a short period would be a useful means of testing concealed weevil- 

 infestation. The general advantages of air-tight storage are briefly 

 summarised, and in conclusion, the importance of this method is 

 urged as a means of maintaining a reserve of cereals in case of war 

 or failure of crops. 



Dendy (A.) & Elkington (H. D.). Report on the Vitality and 

 Rate of Multiplication of certain Grain Insects under various 

 Conditions of Temperature and Moisture. — Rept. Grain Pests 

 (War) Committee, Royal Society, London, no. 7, January 1920, 

 52 pp. [Received 2nd March 1920.] 



The following summary is given of the results of experiments on 

 the vitahty of the most important weevils attacking stored grain : — 

 Under suitable conditions of temperature and moisture and with an 

 abundant supply of wheat, Galandraoryzae and C. granaria show a very 

 high rate of increase and breed all the year round. The optimum 

 temperature for the breeding of Calandra oryzae and G. granaria is 

 about 82° F., for Rhizopertha dominica somewhat higher. At all 

 temperatures and under all conditions, when breeding takes place 

 at all, Galandra oryzae increases much more rapidly than G. granaria, 

 the maximum observed for the former species being a 700-fold increase 

 in 16 weeks, at an average temperature of 82-5 ° F, For this reason 

 G. oryzae is a more serious danger than G. granaria, unless indeed in 

 the British Isles the higher rate of increase is counter-balanced by 

 the higher death-rate of the adults in winter. At ordinary room 

 temperature in the British Isles both Galandra oryzae and G. granaria 

 multiply only during the warmer months of the year, the lower 

 temperature limit for multiphcation being probably about 65° F., 

 while for Rhizopertha it is probably about 70° F. At ordinary room 

 temperatures nearly all adults of Galandra oryzae are killed ofE during 

 the winter, but large numbers of larvae survive in the interior of the 

 grains. 



The adults of Galandra granaria, on the other hand, survive the 

 winter in large numbers, the death-rate being httle, if any, higher 

 than at other times of the year. The adults of the three species show 

 remarkable differences in their susceptibihty to cold. After being 

 kept at a temperature of 33-36° F. for 11 days, 91 out of 100 G. granaria 

 recovered, only 3 out of 100 G. oryzae showed very feeble signs of Hfe, 



