14 MONTANA EXPERIMENT STATION BULLETIN 384 



Sawtooth Grain Beetle (Oryzaephilus surinamensis (L.)). — 

 This is a slender, flat, light- to dark-brown beetle which is also 

 world-wide in its distribution. The sides of the thorax bear a num- 

 ber of saw-tooth-like projections, from which the insect gets its 

 common name. Both in the larval and adult stages it attacks grain 

 and grain products, but it is not so important a pest as the granary 

 weevil. It has been found in the State in Belgrade, Billings, Boze- 

 man, East Helena, Missoula, and Ronan. 



Flat Grain Beetle (Laemophloeus sp.) . — This is the smallest of 

 the grain-infesting insects which has been found in the State. It 

 is about one-sixteenth of an inch long, flat, elongate, and reddish 

 brown. It apparently cannot live in sound grain, usually following 

 up the damage caused by other grain insects or infesting grain or 

 meal which is out of condition. The genus has been found infesting 

 grain or grain products at Belgrade, Billings, Chinook, Havre, and 

 Hardin. 



Broad-Horned Flour Beetle (Gnathocerus cornutus (F.) ) . — 

 This beetle is about one-sixth of an inch in length. It gets its name 

 from the mandibles of the male which extend in front of the head 

 conspicuously and curve inwardly. It is reddish brown in color. It 

 may be found in grain but prefers meal or flour. Although it is 

 found throughout the world, it is comparatively rare in the Great 

 Plains region and in Montana we have a single record from Deer 

 Lodge. 



Confused Flour Beetle (Tribolium confusum Duv.). — The con- 

 fused flour beetle is a shiny, reddish-brown beetle, flattened and 

 oval in shape, about one-seventh of an inch long. It is a very general 

 feeder on grain and grain products, and is probably the most import- 

 ant and destructive of the pests attacking flour in the United States. 

 It may be found wherever grain or grain products are stored, es- 

 pecially in flour mills and in homes. We have records of extreme 

 abundance in houses in various parts of the State. It is generally 

 distributed over the world, and has been reported in Montana from 

 Bozeman, Butte, Forsyth, Great Falls, Missoula, Redstone, Turner, 

 and Wolf Point. Accidental ingestion of these pests by humans 

 is not an uncommon occurrence. Investigations recently reported 1 

 from the Montana Agricultural Experiment Station indicate that 

 cooked confused flour beetles in all stages when consumed in oat- 

 meal are not injurious to humans, even when eaten in rather large 

 doses. 



Foreign Grain Beetle (Ahasverus advena (Waltl.) ) . — This tiny, 

 robust, reddish-brown insect seldom if ever attacks clean, dry grain. 

 It is, therefore, not an important pest in stored grain, preferring 

 damp mouldy material and feeding on the moulds present. It is 

 widely distributed throughout the world, but in Montana has been 

 found only at Amsterdam, Custer, and Billings. 



1 Mills 1 H. B. and Pepper, J. H., J. Econ. Ent. Vol. 32, No. 6. pp. 874-875, 

 1940. 



