A2o Journal of Agricultural Research voi.xx, no.6 



but may sometimes remain within to feed. In winter months individuals 

 have been observed to remain within the grain for as long as a month 

 before cutting their way out. 



NUMBER OF MALES AND FEMALES 



Males and females are apparently produced in very nearly equal 



numbers. Of i ,000 bred specimens examined 52 per cent were females 



and 48 per cent males. The majority of the specimens examined were 



bred during the later months of the year when the percentage of females 



produced was slightly higher. During the early months of summer 



more males were bred than females. Whether these conditions hold 



true always can not be determined until many more specimens have 



been reared and examined. 



COPULATION 



Copulation takes place within a day or two after emergence, one 

 female weevil being observed in copula two days after assuming adult 

 form. Copulation is frequent. It occurs rather often during the day- 

 time but more frequently at night. 



PARTHENOGENESIS 



Unfertilized female weevils, as previously reported by Hinds and Turner 

 (2), do deposit eggs that are fertile. The rate of oviposition is very 

 much lower, however, than with fertilized females, and very few of the 

 eggs hatch and produce grubs. 



LIFE CYCLE AND NUMBER OF GENERATIONS 



The period from egg to adult during the warm months of the year 

 averages 28 days, which together with a preoviposition period of 7 days 

 gives a life cycle of approximately 35 days. In some cases the life cycle 

 is completed in a much shorter period, one reared individual completing 

 the cycle in 30 days. On the other hand, the life cycle may be very 

 considerably prolonged on account of unfavorable food and weather 

 conditions. 



Table III presents the life-history data of 30 weevils bred at various 

 times of the year and shows the variation in the length of the stages 

 from egg to adult at different seasons. 



In Florida there are usually about seven full generations a year, six 

 during the period from April to November and one from December to 

 March. 



MULTIPLICATION 



Several calculations have been made and published of the theoretical 

 number of the progeny of a single pair of weevils. Owing to lack of 

 information on the rate of oviposition, the number of eggs laid, and the 

 length of the life cycle, the number has in some cases been greatly under- 

 estimated and in other cases greatly overestimated. From the data 

 given in Table II it is to be seen that the average female weevil lays 



