The Indian Wheat and Rice Weevil, 



p The larva transforms into a pupa (fig-. 3) within 



the grain without making any perceptible opening 



The perfect insect (figs. 1 and 2) is a small dark brown beetle about 

 The Beetle ^"^ v(\.xi\. {I inch) long and a little more than 1 m.m. 



broad. The head is produced into a rostrum, slightly 

 curved, and marked with coarse longitudinal furrows, composed of some- 

 what irregularly disposed pits. The antennse are elbowed between the 

 long basal joint and the six-jointed stock, and terminate in an oval club. 

 The eyes are lateral and black. The top of the head is finely punctured 

 and the prothorax more coarsely so, the punctures decreasing in size 

 towards the middle line which is comparatively smooth. The elytra are 

 striated with coarse punctures, and each has one rust red coloured spot 

 on the shoulder and anothor behind the middle, which are very variable 

 in size and shape. The terminal portion of the abdomen is free, and the 

 wings are weak and apparently ill-fitted for flight. The underside of the 

 insect is uniform in colour with the upperside; the whole of the body and 

 legs being covered with punctures throughout, and sprinkled with short, 

 yellow stubbly hairs that are not visible in all lights. 



The first considerable opening in the integument of the grain is 

 made when the imago (or perfect beetle) quits the pupa case and cuts its 

 way out of the grain, leaving a hole about one millimeter in diameter 

 leading into the considerable chamber, previously occupied first by the 

 larva and afterwards by the pupa, and into which the beetle frequently 

 creeps for shelter. Until the actual emergence of the beetle, infested 

 grain, though it is somewhat lighter in weight, is superficially almost 

 exactly like sound grain, as the hole made by the female, in depositing 

 her eggs, is almost imperceptible ; and to this, the fact that wheat is 

 supposed to be practically free from weevils until the end of June, may 

 probably be attributed. What is suspected by the writer being that 

 about the end of June is the time that the first generation of beetles 

 emerges from the grain. The time taken for the egg to develop into 

 the perfect insect would appear to be from about six weeks to two mouths. 

 The rate of development, however, probably depends to a great extent on 

 temperature, as some weevils reared in England required 13 months^ 

 for the completion of a single generation. 



Some beetles kept in the Indian museum were found eouplino* iu 



January, but there is probably no very definite time for this operation to 



take place, as they have been observed in England coupling in September.* 



The wheat and rice godowns in Calcutta, visited in J«inaary of this 



year (1888), were simply swarming with the beetles, whx;h were to bo 



' Entomologist, XII, 1879. 



