154 E. C. Cotes — ExJdhits Bice and Wheat Weevils. [June, 



in temperate climates is only able to develop under exceptional cir- 

 cumstances, and therefore it does relatively bat little damage, wbile out 

 here in India it is to be found in every grain-dealer's godown and wher- 

 ever wheat or rice is exposed to the air, whether in sacks or bulk. 



The life history of the weevil is briefly this. The female weevil 

 bores a minute hole in the grain of wheat or rice, as it lies in the store 

 and deposits a single egg in it, covering up the hole with saliva and dust, 

 so as to make it almost invisible, thence it goes on to other grains and 

 deposits a single egg in each, laying in all some 150 eggs. Out of each 

 egg soon creeps a tiny white grub which bores its way into the grain, 

 but does not damage the integument, so that the grain continues to look 

 quite sound. When it is foil fed the grub sheds its skin and becomes a 

 pupa. The pupa lies dormant inside the grain until it is ready to trans- 

 form into the perfect insect, when it wriggles out of its pupal skin and 

 becomes a weevil. This weevil cuts its way out through the skin of the 

 grain and is then ready to commence a new generation. 



We thus see that from the time the egg is laid to the emergence of 

 the perfect insect, the grain is apparently quite sound, and hence it is 

 that the connection between the original weevils and the generation of 

 their offspring which cut their way out of the grain, is usually quite 

 lost sight of, the native dealer believing that the weevils appear from 

 outside and eat up the wheat. And this period of incubation (as it 

 were) accounts, I think, for the many stories one hears of weevils 

 appearing in clean wheat stored in a clean godown, the explanation 

 being that the wheat may have been already affected by eggs, larvse or 

 even pupas of the beetle before it was put into the clean godown. 



Most of the weevils cut their way out of the grain during the rains, 

 and consequently it is then that the weevils are generally noticed for 

 the first time, although the mischief had been going on for weeks or 

 even months while the grub was eating and growing inside the grain, 

 without, however, any sign of its presence being visible externally. 



The cultivator succeeds in protecting his wheat by storing it in pits 

 or mud erections, which he lines with broken straw and chaff from the 

 threshing-floor, or even with sand, covering up the whole carefully with 

 earth. Preserved in this way his grain lies unharmed by weevil in 

 some cases for many years. It is, however, after it leaves his hands, when 

 the wheat find its wa.y into the dealers' godowns, that it is invariably 

 attacked. 



Much the same is the case with rice, which appears to be quite free 

 from weevil as long as it remains in the village granaries where it is 

 stored in the husk, but which becomes affected as soon as ever it is 

 taken out of the husk and stored in the dealers' godowns. 



