716 PROCEEDINGS OF THE THIRD ENTOMOLOGICAL MEETING 



lapping and the insect has been observed to emerge as an adult in all 

 the months from July to April. 



This seasonal life-history coincides with the amount of damage 

 done by the insect during different periods of the year. The greatest 

 damage occurs between August and November or December. The 

 damage continues though in a slightly smaller degree until about Feb- 

 ruary, and it is the least in the hot weather. Although by about Decem- 

 ber actual breeding decreases it should be remembered that the adults 

 also damage the grains by boring into them for the purpose of feeding. 

 The enormous number of weevils present in the store about this time 

 more than compensates for the slower rate of breeding. 



The number of eggs which the weevil is capable of laying has not 

 been determined very accurately. Hinds and Turner had a maximum 

 number of 417 in Alabama, Barnes and Grove had 60 in the Punjab in 

 October and we had 88 at Pusa in February-March. The seasons are 

 observed to have a great effect on the rate of development of the insect 

 and most probably have some effect on the number of eggs which will 

 be found to be more in August-September. 



The adult weevils ordinarily live for about five months and in the- 

 course of their whole hfe they are capable of causing a loss of about 

 50 per cent, in the weight of wheat grains simply by feeding. 



The loss in the weight of wheat grains caused by the grub, which 

 feeds and develops inside until it emerges out of the grains as an adult, 

 is about 30 per cent. 



There is a good deal of difference of opinion as regards the amount 

 of loss caused by the rice weevil. In this respect it is not possible to 

 make a general statement. As will appear from the records of experi- 

 ments given elsewhere in this paper the damage is very serious in small 

 lots of grain and its percentage decreases with the increase in the bulk 

 of the grains concerned. Thus for a given period, say one year, the 

 loss in a lot of one maund of wheat may be more than 75 per cent., 

 while in a lot of 500 maunds it may be as small as 4 or 5 per cent. Small 

 lots suffer most. Therefore the majority of the cultivators who stock 

 only small quantities are the greatest sufi'erers. 



Rhizopertha dominica. (Plate 101.) 

 This insect is not observed ordinarily in the store to do as much 

 damage as the rice weevil. But under certain conditions it is capable 

 of doing far greater damage and in a much shorter time than the latter 

 insect. It does not infest the grain if free air finds access into the 

 storage receptable. If however the vessel is made airtight or fairly 

 so it finds the ideal conditions for breeding. The storage experiments 



