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Washington, D. C. PROFESSIONAL PAPER ‘JULY, 1922 
BROAD-NOSED GRAIN WEEVIL. 
By Ricuarp T. Corron, 
Scientific Assistant, Stored-Product Insect Investigations, Bureau of Entomology. 
CONTENTS. 
Page. Page 
TARE OGUICLION aero ee ere ecm. 218 18 20 PAT ASI LES see pen rere sera ae ee a page ee Bey 8 
Origin and economic history................- 2iyhe Conte olwmeasules= mena. eam ae esa ori ae 8 
Present known distribution...............-. 2 | Technica] description of immature stages. ... 8 
MU QOC Me eee a oe cine oisiae Soe Sia seine ee Sans 2h teratune Cited sacs ese ee ete nt oe 10 
BI CVHISLONY aa aaeiis coccinea cence oe acelaae acm nisass 33. | 
INTRODUCTION. 
The broad-nosed grain weevil, Caulophilus latinasus Say, has 
received but little attention from economic entomologists, and prac- 
tically nothing has been published on the biology of this insect. It 
is 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 
caused by the rice weevil, Sitophilus oryza Linn. 
The damage caused by the broad-nosed grain weevil is more than 
has been generally supposed. While more often found infesting 
stored corn and chick peas, it commonly attacks a variety of seeds 
and cereals. Infested seeds are quickly reduced to a powdery mass 
_ by the combined efforts of the grubs and adult weevils. 
It is interesting to note that whole grain or seed of a medium degree 
of hardness is entirely immune from the attack of this weevil. The 
writer has many times confined weevils with whole grain and chick 
peas, with the result that invariably the weeviis died from starvation 
without being able to penetrate the grain. 
The broad-nosed grain weevil, however, is often associated with 
the common rice weevil, Sitophilus oryza, and the attack of the com- 
mon rice weevil makes it a simple matter for its weaker associate to 
reach the softer portions of the grain. Cracked, damaged, or soft 
seed is quickly infested by the broad-nosed grain weevil. 
The following notes on the life history and habits of this weevil 
were made at Orlando, Fla., during 1919, 1920, and a part of 1921. 
103755—22—Bull. 10851 
