THE CAMPHOR THRIPS. 
15 
tip as the egg moved along, the egg easily slipping out when it reached 
the end. The female immediately crawled away without looking at 
the egg. On another occasion a female crawled up to the top of a 
limb in a jar and immediately deposited an egg on the cut surface. 
Then she at once crawled away, the entire operation requiring no 
more than 30 seconds. 
Rate of oviposition and number of eggs laid. — The rate of oviposition 
is dependent to a considerable extent on the weather. Many more 
eggs are laid on bright warm days than on cloudy or cold days. 
The average for 20 individuals in summer was 5.1 eggs per day 
throughout the egg-laying period, while in winter there was an 
average of 4.19 per day for 20 individuals. After a brief preoviposi- 
tion period amounting to 3.2 days on the average in summer and 7.4 
days in winter, the females begin egg laying. The number of eggs 
laicl per day has varied from none up to 13 in one case, but will average 
about 4 or 5. As will be noted in Table 3, some females are much 
more productive than others, even when kept under identical condi- 
tions. In the breeding jars some insects have laid from 7 to 10 or 11 
eggs per day over a considerable period. Toward the end of their 
life the number of eggs per day diminishes, and finally ceases, being 
followed by a brief postoviposition stage. This period of inactivity 
varied from 1 to 14 days, with an average of 4.4 days for summer 
and 2.7 days for winter. The average length of the egg-laying stages 
was 90.4 days and the average total number of eggs 463.7 in summer. 
For winter the average of the egg-laying stages was 73.3 and the 
average total number of eggs 307. The greatest number of eggs laid 
by an individual thrips was 684. 
Table 3. — Length of life of adults of the camphor thrips, showing length of egg-laying, 
preoviposition, and postoviposition periods, together with number of eggs laid. 
IN SUMMER. 
Record No. 
Average . 
Date 
adult 
emerged. 
1921. 
Aug. 22. 
Aug. 23. 
Aug. 22. 
Aug. 23. 
Aug. 24. 
...do... 
Aug. 23. 
Aug. 24. 
...do... 
...do... 
Aug. 25. 
Aug. 24. 
Aug. 25. 
Aug. 26. 
..do... 
...do... 
Aug. 28. 
Aug.27. 
..do.. . 
Aug. 31. 
Date 
first egg 
laid. 
1921. 
Aug. 25. 
Aug. 26. 
...do... 
...do... 
Aug. 27. 
...do... 
...do... 
...do... 
...do... 
...do... 
Aug. 28. 
Aug. 29. 
...do... 
...do... 
...do... 
...do... 
Aug. 30. 
...do... 
...do... 
Sept. 3.. 
Length 
of pre- 
oviposi- 
tion 
period. 
Days. 
3 
3 
4 
3 
3 
3 
4 
3 
3 
3 
3 
5 
4 
3 
3 
3 
2 
3 
3 
3 
Date 
last egg 
laid. 
1921-22. 
Oct. 24.. 
Nov. 26. 
Nov. 3.. 
Oct. 24.. 
Oct. 29.. 
Oct.l.. 
Dec. 20. 
Oct. 4.. 
Dec. 27. 
Oct. 14.. 
Dec. 15. 
Mar. 4.. 
Dec. 27. 
Jan. 3. . 
Oct. 29.. 
Jan. 2:;.. 
Nov. 10. 
Jan. 5. . 
Dec. 16. 
Oct. 21.. 
Length 
of egg- 
laying 
period. 
Days. 
60 
92 
69 
59 
63 
35 
115 
38 
122 
48 
109 
187 
120 
127 
61 
147 
72 
12a 
108 
48 
90.4 
Date of 
death. 
1921-22. 
Oct. 26. 
Nov. 30. 
Nov. 5.. 
Oct. 26. 
Oct. 31. 
Oct. 4.. 
Dec. 23. 
Oct. 8. . 
Jan. 3. . 
Oct. 21. 
Dec. 19. 
Mar. 8.. 
Jan. 3.. 
Jan. 9.. 
Nov.l.. 
Feb. 2.. 
Nov. 16. 
Jan. 9.. 
Dec. 19. 
Oct. 26. 
Length 
ofpost- 
ovi posi- 
tion 
period. 
Days. 
2 
4 
2 
2 
2 
3 
3 
4 
7 
7 
4 
4 
7 
6 
3 
10 
6 
4 
3 
5 
Total 
length 
of life. 
Days. 
65 
99 
75 
64 
68. 
41 
122 
45 
132 
58 
116 
96 
.31 
13ii 
67 
160 
80 
135 
114 
56 
9S 
Total 
num- 
ber of 
eggs 
laid. 
488 
559 
484 
434 
360 
280 
496 
242 
656 
136 
516 
684 
4(15 
50S 
B0 
672 
521 
578 
538 
227 
463.7J 
4 
