72 



PERIOD OF OVIPOSITION. 



With the exception of hibernated weevils, it appears that oviposi- 

 tion begins with most females within a week after they begin to feed 

 and continues uninterruptedly until shortly before death. While 

 females frequently deposit their last eggs during the last day of their 

 life, a period of a few days usually intervenes between the cessation 

 of oviposition and death. 



In the case of 52 hibernated females the actual period of oviposition 

 averaged about 48 days, the maximum being fully 92 days. 



In an average made with 21 females of the first' generation the 

 actual period was almost 75 days, the maximum period being 113 days. 



The average period for the females of the first two generations 

 appears to be longer than that for any other. In the third generation 

 the average period for 11 females was 58 days, the maximum being 99 

 days, and in the fifth generation for 5 females the period averaged 48 

 days, with the maximum only 62. 



The approach of cold weather cuts short the activity of the weevils, 

 which become adult after the middle of August, thereby decreasing 

 the length of their oviposition period. Weevils which pass through 

 the winter actually live longest, but as it must take more or less vital- 

 ity to pass through the long hibernation period their activity in the 

 spring is thereby lessened. 



The weighted, average period of oviposition of the 89 females here 

 mentioned is 55.6 days. 



DOES PARTHENOGENESIS OCCUR? 



To test the possibility of weevils reproducing parthenogenetically, 

 12 individuals were isolated from the very beginning of their adult 

 life. Each beetle was supplied daily with fresh, clean squares and 

 careful watch was kept for eggs. The first noticeable point was that 

 no eggs were found till the weevils were about twice as old as females 

 usually are when they deposit their first eggs. After they began to 

 oviposit, it was found that a very small proportion of the eggs were 

 deposited in the usual manner within sealed cavities in the squares, 

 but nearly all of them had been left on the surface, usually near to 

 the opening to an empty egg puncture. This same habit was shown 

 by a number of females, and so can not be ascribed to the possible 

 physical weakness of the individuals tested. The number of eggs 

 deposited was unusually small, and those few placed in sealed cavities 

 failed to hatch. After somewhat more than a month had been passed 

 in isolation, one pair was mated to see if any change in the manner of 

 oviposition would result. The very next eggs deposited by this fer- 

 tilized female were placed in the square and the cavity sealed up in 

 the usual manner, showing that her infertile condition had been the 

 cause of her abnormal manner of oviposition. 



A much more extensive series of experiments along this line is 

 desirable and will be made. 



