THE ROSE APHIS. 
Table I. — Reproduction 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, 
Number of 
young. 
4 
1909: 
Oct. 
o_ 
33 
Average per clay 5^ 
Total. 
Date of birth of female unknown; 
date of birth of first young un- 
known: 
Nov. 3 6 
4 4 
5 2 
7 4 
s _o_ 
Total 16 
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 
15-1G 9 
17 2 
18-19 3 
20-21 6 
22-23 5 
25 2 
28 ( 3 ) 
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 _0_ 
Total 48 
Average per day, about 6 
1 Aphis lost. 
2 Period from birth to reproduction, 18 
s Aphis dead. 
Date of birth, of female unknown; 
gave birth to first young Nov. 
19,1909: Number of 
youug. 
Nov. 19 2 
20 .. 2 
21-22.... 4 
23 4 
24 2 
25 .\. 2 
26 (? 6 ) 
27 2 
28 2 
29 2 
30 Q) 
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 
24. 
25. 
26. 
27. 
28. 
Total 
Average per day . 
o 
4 
3 
4 
C) 
29 
3+ 
Wingless female born Nov. 18, 1909; 
gave birth to first young Dec. 6, 
1909 : 2 
Dec. 7-8 3 
8 • -, ( 5 ) 
10-11 3 
13... 7 
15-16 7 
17 3 
18-19 6 
20 1 
21 - ( 3 ) 
days. 
Total 30 
Average per day 2 
* Up to date. 
5 Rain. 
