OF WASHINGTON, VOLUME XVI, 1914 2~> 



to July 16. The average period of development to maturity ranged 

 from 16 days from eggs laid June 6 to 12.4 days from eggs laid 

 June 26. The offspring numbered 20 males and 20 female-. 



In the third series the males of thurberice were placed with hi- 

 bernated females of grandis collected in the field. These females 

 were already fertile as they began oviposition almost immediately. 

 In 200 weevil-feeding days, 454 feeding punctures were made,' 

 with the average per individual 2.2 per day. In 94 weevil-oviposi- 

 tion days 717 eggs were laid with the average 7.6 eggs per day 

 and a maximum of 16. Eggs were obtained from May 22 to July 

 7. The offspring were bred from June to July 20. The average 

 period of development to maturity ranged from 20 days for eggs 

 laid May 28 to 12 days for eggs laid June 6. The offspring 

 numbered 137 females and 145 males. 



The weevils with the female thurberice strain in the second 

 series averaged day for day a fraction of a day shorter develop- 

 mental period than the offspring of the female grandis which may 

 have had a male thurberice strain in the latter part of the experi- 

 ment. 



The offspring of the male grandis, female thurberice breedings 

 were interbred. In 22 weevil-oviposition days 179 eggs were laid, 

 with an average of 8.4 per day and a maximum of 15. Eggs were 

 obtained from July 2 to 17 and the offspring were bred from July 

 16 to 28. The average period of development to maturity ranged 

 from 15 days for eggs laid July 3, to 11 days for eggs laid July 15. 

 The offspring numbered 12 females and 20 males. 



The offspring of the male thurberice, female grandis breedings 

 were interbred. In 72 weevil-oviposition days, 253 eggs were 

 laid, with an average of 3.5 per day and a maximum of 15. Eggs 

 were obtained from June 24 to July 11 and the offspring were bred 

 from July 7 to 22. The average period of development to maturity 

 ranged from 11 to 18 days. The offspring numbered 32 females 

 and 25 males. 



A comparison of average development dating from 5 day ovi- 

 position periods is available in five combinations for July 1 to 

 5. The offspring of native grcniil/s took 1^.1 days; of female 

 grandis by male thurberice 12.4 days; and of the male and female 

 offspring of the female grandis, male thurberice combination 14.0 

 days; of female thurberice by male grandis 12.6 days; and of the male 

 and female offspring of the female thurberice, male gmm/is combi- 

 nation 14.2 days. The accompanying table (Table I) gives t In- 

 complete record. 



In September more material was received from Arizona. < Om- 

 plete studies of this material have not been made but the follcm inu 

 results have already been obtained (see Table II). 



