INSECTS INJURIOUS TO CEREALS 



237 



other of the stored grain insects. This insect is commonly 

 known among the farmers as the " grain- weevil " or the 

 "saw-tooth weevil." 



The beetle, itself, is a minute, flattened, reddish-brown 

 beetle about one-tenth of an inch long. The thorax is the 

 distinguishing feature of this insect. 

 It is long and narrow and bears on 

 each lateral margin a number, usually 

 6, of conspicuous tooth-like projec- 

 tions. It is this characteristic that 

 gives the beetle the name of "saw- 

 tooth weevil." There are three 

 strong ridges on top of the thorax 

 with two wide 

 sunken areas, one 

 each side of the cen- 

 tral ridge. The wing 

 covers are longi- 

 tudinally ridged 



with the areas be- FIG. 70. The saw- 

 tween finely punc- ** ^-in-beetle. 

 tate. The head is 

 also densely covered with punctures. 

 The larva (Fig. 71) is somewhat 

 , flattened and has a transverse rec- 



tiu. 71. Larva of 



saw-toothed grain- tangular chitimzed area on the dorsal 



beetle, enlarged. side Q f each body se g m ent. On the 



thoracic and anterior abdominal seg- 

 ments these rectangular areas may be divided in two 

 by a whitish line through the middle. The larva, when 

 living in granular material, like meal, usually builds a 

 thin case out of the particles and the whitish pupa may 



