RICE WEEVIL, (CALANDRA) SITOPHITUS ORYZA 



By Richard T. Cotton, Scientific Assistant, Stored-Product Insect Investigations, 

 Bureau of Entomology, United States Department of Agriculture 



INTRODUCTION 



As early as 196 B. C. mention is made. of the ravages of weevils 

 in stored wheat (9). 1 Whether the species referred to was Sitophilus 

 oryza L. or the closely allied granary weevil 5. granarius L. we do not 

 definitely know. The latter species, however, is thought to be the older 

 and is presumably the one referred to. However that may be, since 

 about the middle of the eighteenth century, when it was discovered in 

 Europe, 5. oryza has everywhere attracted the attention of scientists, 

 and innumerable accounts have been written concerning its ravages. 

 It is not the purpose of the writer to review at this time the extensive 

 literature relating to this weevil; it will suffice to state that the early 

 accounts are very general in character and the majority of the later 

 ones little more than repetitions of the earlier observations. The publica- 

 tion of Hinds and Turner (6) in 191 1 on the biology of the rice weevil 

 gives us the only really definite information that we had regarding the 

 life and habits of this species. A general presentation of the economic 

 problem centered in the rice weevil was given in 191 9 by Back (1) in a 

 publication of the Department of Agriculture. It is with the purpose of 

 adding to our knowledge of this cosmopolitan insect that this paper is 



presented. 



ORIGIN AND DISTRIBUTION 



The rice weevil, Sitophilus oryza, so called because of its discovery 

 breeding in rice, is thought to have originated in India. It was carried 

 by commerce to Europe at an early date, where it was subsequently 

 found and described by Linnaeus in 1763 (7, p. 395). 



At present it is perhaps the most widely distributed of known insects, 

 being found in all parts of the world where grain is used. In North 

 America it is reported from Florida to Alaska, though it is found in its 

 greatest abundance in the South Atlantic and Gulf States. 



DAMAGE CAUSED 



From time immemorial the rice weevil has taken its yearly toll of the 

 grain crops of man. The total amount of rice, corn, wheat, barley, rye, 

 etc., that has been destroyed by this weevil alone is almost beyond con- 

 ception. 



1 Reference is made by number ("italic) to "Literature cited," p. 422. 



Journal of Agricultural Research, Vo1 - xx - No - s 



Washington, D. C P. ec - Jf' r *°_ 



vu 



(409) 



Key No. K-87 



