756 PROCEEDINGS OF THE THIRD ENTOMOLOGICAL MEETING 



Of ttie receptacles in use among the ordinary house-holders for 

 storage of grain, gunny bags are the worst as they expose the grain to 

 insects all over their surface. 



The various types of earthen vessels, mud-bins and bamboo-bins 

 cannot be made insect-proof. 



Attempts are often made to make earthen vessels insect-proof by- 

 plastering down their covers with mud. They cannot be made insect- 

 proof in this manner, as some of the worst pests {e.g., Bhizo'periha domi- 

 mca) can work their way through the mud plaster. As will appear 

 from the records of experiments with wheat given above, the grain 

 (especially the cereals) in vessels closed in this maimer is liable to be 

 attacked by two seiious pests, viz., Wiizojjertha dominica, which does- 

 the greatest damage in the shortest time of all the store pests, and {2} 

 Calandra oryzce, the ordinary rice weevil, which, in addition to the actual 

 damage by feeding, causes the entire quantity of grain, including the 

 unaffected ones, to feiment and rot owing to the moisture and heat 

 generated by it while breeding in the grain. In vessels which are not 

 thus closed and into which free air can have access the grain (cereals)i 

 is liable to be attacked only by the rice weevils with this advantage 

 that no fermentation and rotting are set up, as the moisture and heat 

 generated by the insects escape. Therefore open-mouthed unclosed 

 vessels are preferable. 



There is no treatment known which can immunize the grain against 

 insects even for a few months. Safety lies in storing the grain in open- 

 mouthed unclosed receptacles and at the same time adopting such 

 methods as will prevent the insects having access to it. This has been 

 found to be practically possible by keeping the grain in open-mouthed 

 receptacles with solid walls and bottom through which no insects can 

 have access, and by keeping the grain covered at the top with a layer 

 of dry fine sand. 



Plate 123, figs. 1 and 3 show how the grain should be stored in 

 earthen pots and kerosine tins or bins. The sand percolates down and 

 exposes the grain at the top. This should be guarded against at the 

 time of storage by making the sand go down as much as possible by 

 shaking or striking the sides of the receptacles. A layer of about 1 to 

 2 inches of sand should stand at the top covering the grain always. 



The sand has an additional advantage. Some of the peSts (especially 

 the Pulse Beetles) infect the seeds while still in the field an d the insects 

 which remain inside the seeds are brought into the store a nd afterwards 

 breed there. The sand prevents such insects from breeding and it has 

 been found practically that the msects come up to the top of the sand 



