INSECTS INJURIOUS TO STORED GRAINS 



187 



will often be found in that of corn. Xot only do the larvae 

 injure the grain, but the beetles feed upon it, and then hollow 

 out a shelter for themselves within the hull. The beetles are 

 quite long-lived, and thus do considerable damage. The egg- 

 laying period is equally long, and as there are three or four broods 

 in the North and six or more in the South, it has been estimated 

 that the progeny of one pair would amount to 6000 insects in a 

 single season. 



Grain-beetles 



Another beetle very common in the granary, but of quite 

 different appearance, is the Saw-toothed Grain-beetle * (Fig. 137). 

 It is a cosmopolitan 

 pest and is also nearly 

 omnivorous. The 

 beetle is only about 

 one-tenth of an inch 

 long, very much flat- 

 tened, of a dark-brown 

 color, and may be 

 easily recognized by 

 the six saw-like teeth 

 on each side of the 

 thorax, The larva is 

 of a dirty-white color, 

 and quite dissimilar 

 from that of the gra- 

 nary weevil. Having 

 , , 



about, it is not satisfied 

 with a single seed, but 

 runs about here and 



there, nibbling at several. When full grown the larva glues together 

 several grains or fragments into a little ease, and inside of this trans- 

 forms to the pupa and then to the beetle. In early spring this life 

 * Silvanus surinamensis Linn. Family Cucujidoe. 



FIG. 136. The grain weevil (Cakindra granaria): 

 a, beetle; b, larva; c, pupa, d, the rice weevil 

 (C. oryza) : beetle all enlarged. (After Chit- 

 tenden; U. S. 



