718 rnocEEDiNGs of the third entomological meeting 



procure sustenance by nibbling the grains. A number of the beetles 

 •confined with wheat grains were observed to nibble the germ of the 

 •grains. This was, however, exceptional. Ordinarily they do not attack 

 sound grains. 



They are, however, a serious pest of ground wheat {atta, maida, 

 suji), ground rice, oatmeal, etc. In addition to the damage they cause 

 they impart to the stufE a characteristic nauseous smell and taste which 

 lowers its value as food and consequently also its price. In cases of 

 l)ad infection the attacked material may be uneatable. In the trade, 

 atta is stored and sold in gunny bags. A visit to a store-house contain- 

 ing such bags between July and November reveals the presence and 

 working of this insect through the dust which oozes out of all sides of 

 the bags and covers them entirely. Atta, suji, etc., are found to swarm 

 with these insects, especially their grubs, about September-October. 

 The insect seems to be more active in the rainy season than at other 

 "times of the year. Fresh generations occur after about a month. 



Tenebroides mauritanicus (Plate 104). 



These brown beetles and their large fiat white grubs easily attract 

 attention when they are present among the grains. They occur more 

 commonly in rice and wheat than in other grains. 



Various opinions have been held regarding the part played by this 

 insect in the store, some being distinctly of the opinion that its presence 

 is beneficial and therefore desirable on the ground that it preys upon 

 other grain pests. It has been ascertained by experiments that the 

 grubs feed only upon the grains and not upon any insect. The adult 

 beetles prey upon adult rice weevils {Calandra oryzce) but feed upon the 

 grains as well even when adult rice weevils are present. Besides, their 

 growth is so slow, as will appear from the short details of life-history 

 given below, that their usefulness as agents of destruction of other pests 

 is negligible. Therefore they are to be ranked among pests. As pests, 

 however, they are not capable of serious injury on account of the very 

 slow rate of their development. 



Elongated cigar-shaped white eggs with soft membrane, measuring 

 about 1-5 to 2 mm. in length and about 0-25 mm. in thickness, are 

 deposited in clusters among the grains. In orcUnary weather they 

 hatch after about 6 days. The flat white grubs are sluggish in nature 

 and feed by gnawing the grains, consuming the farinaceous matter and 

 sometimes entering the gnawed grains bodily. They can also feed upon 

 the dust produced from the grains by other pests. 



They develop very slowly and become full grown in the course of 

 -about 10 to 20 months. Pupation takes place either inside the corroded 



