THE EOSE APHIS. 



Table I. — Re-production and development of the rose aphis, Macrosiphum rosae, in 

 southern California, 1909-10. 



Date of birth of female unknown; 



gave birth to first young Oct. 20, 



1909: Number of 



young. 



Oct. 20 4 



21 5 



22 5 



23 7 



24 5 



25 7 



26 : o_ 



Total 33 



Average per day 5£ 



Date of birth of female unknown; 

 date of birth of first young un- 

 known: 



Nov. 



Total. 



6 



4 



2 



4 



■ _0)_ 



10 



Average per day 3+ 



Female born Nov. 18, 1909; gave 

 birth to first young Dec. 6, 1909: 2 



Dec. 6 1 



8 5 



10-11 6 



12 3 



13-14 4 



15-10 9 



17 2 



18-19 3 



20-21 6 



22-23 5 



25 2 



28 («) 



Total 46 



Average per day 2 \ 



Date of birth of winged female, red 

 form, unknown; date of birth of 

 first young unknown: 



Nov. 18 4 18 



19 3 



20 5 



21-22 12 



23 10 



24 _C)_ 



Total 48 



Average per day, about 6 



1 Aphis lost. 



2 Period from birth to reproduction, 18 



3 Aphis dead. 



Date of birth of female unknown; 

 gave birth to first young Nov. 



19, 1909: Number of 



young. 



19 2 



20 2 



21-22 4 



Nov. 



23. 

 24. 

 25. 

 26. 

 27. 

 28. 

 29. 

 30. 



Total 22 



Average per day 2 



Date of birth of wingless female, 

 green form, unknown ; gave birth 

 to first young Nov. 19, 1909: 



Nov. 19 2 



20 5 



21-22 6 



23 5 



24 4 



25 3 



26 (? 5 ) 



27 4 



28 0) 



Total 



Average per day. 



29 

 3+ 



Wingless female born Nov. 18, 1909; 

 gave birth to first young Dec. 6, 

 1909 : 2 



Dec. 7-8 3 



8 ( s ) 



10-11 3 



13 7 



15-16 7 



17 3 



18-19 6 



20 1 



21 ( 3 ) 



days. 



Total 30 



Average per day 2 



4 Up to date. 

 6 Rain. 



