232 JOURNAL OF ECONOiMIC ENTOMOLOGY [Vol. 4 



steadily tliroughout the winter provided the temperature remains 

 sufficiently high. The occurrence of a particularly cold snap, as when 

 temperature falls to below 10° above zero, while it does not exterminate 

 the weevils, still appears to destroy a large part of the immature stages 

 and many adults and thus greatly retards subsequent multiplication 

 and injury by the pest later in the winter. As a rule the greatest 

 damage by these weevils is done before the end of December, in this 

 State, and thereafter to corn that is stored beyond the following April. 



During the winter season, as from December 15 to March 15 the 

 larval stage has been known to be extended to beyond 115 days, or 

 about four months, in spite of the fact that the infested corn was kept 

 in a heated building where the daj^ temperature averaged nearly 60° 

 with the night temperature probably 10° to 15° lower. 



The Adult. — ^As has been said, the adult remains in the pupal cell 

 for several days, usually three to four, for hardening and maturing 

 before it starts to cut its way out of the kernel. Much feeding may 

 then be done within the kernel without any attempt at emergence, 

 so that we cannot reckon the life-cycle from observations based solely 

 upon the time between oviposition and the emergence of the adult. 

 Many weevils perish in their effort to escape from the kernel, being 

 found wedged in the exit hole, usually with only the head, prothorax 

 and forelegs free. 



At an average temperature of about 63°, development from ovipo- 

 sition to the emergence of the adult may take place in about thirty-two 

 days. The general average, however, is rather longer than this 

 and for the first field generation, appears to be about six weeks and 

 for the second field generation between seven and eight weeks. This 

 is between about the first week of August and the last of October. 



The adult rice weevil, or ''black weevil," as it is often called in the 

 South, is a rather slender, cylindrical beetle, averaging in length 

 of body from the front margin of the prothorax to the tip of the 

 body, about 3.5 mm. and for the length of head and snout about 1.6 

 mm. The normal color is a very dark brown or nearly black and is 

 uniform except for four reddish spots located one at each corner of 

 the wing-covers. The prothorax is densely and uniformly punctured 

 as are the elytra (PI. 7, fig. 1). The reddish spots and the puncta- 

 tion serve to distinguish this species from C. granaria. The average 

 weight per weevil is approximately 0.003 gram, or more than 

 150,000 weevils per pound. 



Distinguishing the Sexes. — This is not a difficult matter, although 

 size and color do not appear to indicate it at all. In size, measurements 

 of 20 females shows a body length averaging 3.5 mm. and a head and 

 snout length averaging 1.66 mm. Among 20 males, the body length 



