203 



confinement readily deposited their eggs on the heads of green wheat, 

 generally under the protection of the glumes, the average number 

 among four moths observed being 92. In the warm June days the 

 egg stage lasts from 7 to 9 days. 



Wheat in all stages of development is subject to attacks of the 

 larvae, though under natural conditions few larvae appear early enough 

 to attack the heads before pollination. The larvae upon hatching 

 enter the grain by gnawing through the pericarp and, as they mature, 

 the entire contents of the grain are eaten out. Larvae entering the 

 grain in mid-June require 41 to 49 days before emergence of the 

 adults ; those entering green and milky wheat require 40 to 44 days 

 to complete their development. A diagram shows the generations of 

 this moth and the times of their occurrence. Those appearing at 

 harvest time constitute the second generation, the maximum number 

 being present in early August. AVhen the harvest is gathered late, 

 a small number of moths emerge in the field and give rise to a third 

 generation in September, which is the last to appear in the open. 

 Moths of the second generation that emerge in the barns carry on 

 their depredations through 6 and even 7 generations, so long as the 

 grain is unthreshed and there is no severe weather. The practice 

 of leaving the grain lying in the barn and threshing it only as the 

 straw is needed is conducive to most rapid development of the moths. 



The first essential in control of this pest is to thresh the wheat as 

 soon after the harvest as possible. Grain stored in tight granaries or 

 in good sacks is less liable to repeated attacks and can easily be treated 

 ^^^th carbon bisulphide. Thorough barn sanitation and the elimination 

 or utilisation of all scattered wheat are of extreme importance in 

 checking the pest. Floors and beams should be swept. Poultry 

 are useful in clearing the grain from crevices in the floor. Infested 

 screenings should be ground or immediately used as food for stock, 

 and all grain should be threshed in future in the open to avoid re- 

 infestation of the barn. The author is of opinion that if co-operative 

 early threshing and thorough barn sanitation are practised the use of 

 carbon bisulphide will be found unnecessary. 



In the discussion follo-wnng the reading of this paper, S. cerealella 

 was reported for the first time in Nebraska during the summer of 

 1917 ; while in Kansas the pest is largely controlled in the wheat by 

 early threshing, but is still a serious pest in the chaff, and it is found 

 necessary to fumigate the seed before sowing. Investigations are still 

 being carried on to determine whether the moth can develop in the 

 field throughout the year without passing into the granaries at all, 

 and also whether the insects can be carried into the soil in infested 

 grain. 



How Can the Entomologist Assist in Increasing Food Production ? — 



Jl. Econ. Entom., Concord, N.H., xi, no. 1, February 1918, 

 pp. 106-118. 



In opening the discussion on this subject, Mr. G. A. Dean stated 

 that in Kansas insects cause an annual loss of not less than £8,000,000, 

 fully £5,000,000 of which could be eliminated if the practical methods 

 of control that have been found effective were put into operation. 

 He described a scheme for effective work in insect control, emphasising 

 the necessity for adequate propaganda, for planning and directing 



