438 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 4 



The Life Cycle 



The life cycle of the weevil may properly be divided into three 

 periods: the developmental, preoviposition (the time between emer- 

 gence and the beginning of oviposition), and oviposition periods. The 

 last has already been discussed. The developmental period may be 

 divided into the egg or incubation, larval, pupal and postpupal or 

 teneral adult periods. The last is the time after the casting of the 

 pupal skin, during which the weevil remains in the pupal cell. 



Preoviposition Period 



Data on this period in the life of the weevil was obtained from 43 

 weevils, representing the earliest individuals of generations one to 

 four and the latest of generation one. As far as possible the date of 

 copulation was obtained. This date is, however, very Uable to error, 

 since this act may be repeated between the same two weevils a number 

 of times and even after oviposition has commenced. The time 

 observed to have elapsed between emergence of the female and copu- 

 lation varied in thirteen cases from two to seven days. In one of the 

 two cases, in which seven days had elapsed, the original male weevil 

 died on the sixth day and a new one was substituted. On the seventh 

 day the pair were in copula and two eggs had been deposited. In the 

 other seven day case copulation was also observed on the date of first 

 oviposition. Copulation must, therefore, have taken place sometime 

 before observed, in all probability by the third day. These obser- 

 vations, therefore, mean little except as they show the minimum time 

 required for the proper maturing of the sexes for copulation. 



As mentioned above, the minimum time from emergence of the 

 females to copulation was two days. The male in this pair was, 

 however, one day older than the female, and copulation in this case 

 may have been due entirely to the extreme amour of the male, and does 

 not necessarily mean that the ovaries of the female were ripe for fer- 

 tilization. In two cases the time elapsed between emergence and cop- 

 ulation was three days. In one of these pairs the male was four days 

 old at the time of copulation, and in the other both sexes were of the 

 same age. These three cases would seem to indicate that the normal 

 time necessary for the ripening of the sexual organs in both sexes is 

 about three days. 



The total period from emergence to oviposition varied from five to 

 twenty-three days. The seven longest periods occurred in the weevils 

 taken as the earliest of the fourth generation. Three of these were 

 reared from squares infested by the latest weevils of the first genera- 

 tion and the rest, from those infested by the early third generation 

 weevils. The long time required by these weevils is probably partly due 



