UNITED STATES DEPARIMENT OF AGRICULTURE 



BULLETIN No. 1085 



Washington, D. C. PROFESSIONAL PAPER JULY, 1922 



BROAD-NOSED GRAIN WEEVIL. 



By Richard T. Cotton, 

 Scientific Assistant, Stored-Product Insect Investigations, Bureau of Entomology. 



^Introduction 1 ! Parasites 8 



Origin and economic history 2 ' Control measures 8 



[iPresent known distribution 2 Technical description of immature stages 8 



Food 2 ; Literature cited 10 



Life history 3 1 



CONTENTS. 



INTRODUCTION. 



The broad-nosed grain weevil, CaulopJiilus latinasus Say, has 

 [(received but little attention from economic entomologists, and prac- 

 tically nothing has been published on the biology of this insect. It 



now widespread over Florida and has been reported from Georgia 

 and South Carolina. It is not unlikely that it will gradually spread 

 to other parts of the South and add to the already heavy damage 

 aused by the rice weevil, Sitophilus oryza Linn. 



The damage caused by the broad-nosed grain weevil is more than 

 aas been generally supposed. While more often found infesting 

 stored corn and chick peas, it commonly attacks a variety of seeds 

 :md cereals. Infested seeds are quickly reduced to a powdery mass 

 oy the combined efforts of the grubs and adult weevils. 



It is interesting to note that whole grain or seed of a medium degree 

 •)f hardness is entirely immune from the attack of this weevil. The 

 writer has many times confined weevils with whole grain and chick 

 seas, with the result that invariably the weevils died from starvation 

 svithout being able to penetrate the grain. 



The broad-nosed grain weevil, however, is often associated with 

 ;lie common rice weevil, Sitophilus oryza, and the attack of the com- 

 oion rice weevil makes it a simple matter for its weaker associate to 

 ?each the softer portions of the grain. Cracked, damaged, or soft 

 5eed is quickly infested by the broad-nosed grain weevil. 



The following notes on the life history and habits of this weevil 

 vere made at Orlando, Fla., during 1919, 1920, and a part of 19.21. 



103755— 22— Bull. 1085 1 



