113 



time to propagate they soou convert the flour into a gray useless m 

 A part of the annoyance to purchaser, dealer, and manufacturer is din- 

 to the fact that the insects are highly offensive, a few specimens being 

 sufficient to impart a disagreeable and persistent odor to the infested 

 substance. 



THE CONFUSED FLOUR BEETLE. 



{Tribolium confusum Duv.) 



The most injurious enemy to prepared cereal foods is undoubtedly the 

 above-mentioned species. Singularly enough, in less than two years 

 from the time of its first recognition as a distinct species occurring in 

 this country, this insect had been reported as injurious in nearly every 

 State and Territory in the Union. The divisional experience of a sin- 

 gle year, 1894, shows that more comx^laints are made of injuries by 

 this than of any other granivorous species. Mr. W. G. Johnson, in the 

 American Miller of January 1, 1896, speaking of this insect as a mill 

 pest, says that it Avas the most troublesome species of the year 1895, 

 and expresses the 

 belief that it had 

 cost the millers of 

 the United States 

 over $100,000 in 

 manufactured prod- 

 ucts during that 

 year. 



The mature insect 

 is shining reddish 

 brown in color and 

 resembles in minia- 

 ture the adult of the 

 familiar meal-worm 

 (Tenebrio), which 

 will be referred to 

 further in the fol- 

 lowing pages. It is 

 scarcely a sixth of an inch long, being almost an exact counterpart of 

 the rust-red flour beetle (T. ferrugineum), with which it has been gen- 

 erally confused, but may be distinguished by the structure oi' the 

 antenna', which are only gradually clavate, by its broader head, the 

 cheeks being expanded at the sides and angulated at the eyes. The 

 thorax above is gradually narrowed behind, its hind angles being more 

 or less acute. The adult beetle is shown, enlarged, in the accompanying 

 illustration (fig. 52) at a, and the head and antennae, still more enlarged, 

 at c The same parts of ferrugineum are presented at/for comparison. 



This species, like nearly all the others that frequent the family store 

 room, is what is termed a general feeder. It prefers, however, prepared 

 cereals, and hence is most troublesome in flour, corn meal, oatmeal, 

 2805— Xo. 4 8 



Fig. 52. — Tribolium confusum: a, beetle; b, larva; e, pupa — all enlarged; 

 d, lateral lobe of abdomen of pupa: e, head of beetle, showing an- 

 tenna; /, saint' of T. J'erviujineiua — all greatly enlarged (author's 

 illustration). 



