552 
Journal of Agricultural Research 
Vol. XXIII, No. 7 
OVIPOSIT ION PERIOD 
The oviposition period extends over the greater part of the life of the 
female parasite. Commencing a day or two after emergence it lasts to 
within a week or two before death. The longest oviposition period re¬ 
corded was 73 days, from December 4, 1920, to February 14, 1921, the 
shortest 39 days, from August 2; 1920, to September 9, 1920. 
Eggs are laid at the rate of from 1 to 12 a day, depending upon the 
temperature. During the summer months the oviposition rate is high, 
but in winter the rate decreases to 1 or 2 a day. On the colder days 
oviposition ceases entirely. 
NUMBER OF EGGS LAID 
The greatest number of eggs laid by a single female was 283. These 
were laid in the months of August and September, 1920, over a period 
of 43 days. The lowest number recorded was 51. These were laid dur¬ 
ing the months of December, 1920, and January and February, 1921, over 
a period of 73 days. In general more eggs are laid by the summer gener¬ 
ations of parasites than by those of winter. 
Table I contains data concerning the oviposition period, the number of 
eggs laid, longevity, etc. 
Table I.— Data concerning oviposition and longevity of Aplastomorpha vandinei at 
Orlando , Fla., 1920-21 
No. 
Date para¬ 
site. 
emerged. 
Date first 
egg was 
laid. 
Length of 
preovi- 
position 
period. 
Date last 
egg was 
laid. 
Length of 
ovi¬ 
position 
period. 
Number 
of eggs 
laid. 
Date of 
death. 
Length of 
life. 
1 
July 
28 
July 
29 
Days. 
I 
Sept. 
9 
Days. 
43 
283 
Sept. 
10 
Days. 
45 
2 
July 
29 
July 
30 
I 
Sept. 
21 
54 
258 
Oct. 
11 
75 
*3 
Aug. 
11 
Aug. 
11 
H 
Sept. 
29 
5 ° 
157 
Nov. 
8 
90 
4 
Aug. 
17 
Aug. 
18 
I 
Oct. 
24 
68 
236 
Nov. 
4 
80 
5 
...do. 
...do. 
1 
Oct. 
27 
7 i 
239 
Nov. 
1 
77 
6 
Aug. 
20 
Aug. 
21 
1 
Oct. 
3 ° 
7 i 
279 
Nov. 
12 
85 
7 
Oct. 
15 
Oct. 
17 
2 
Dec. 
22 
67 
93 
Jan. 
10 
88 
8 
Nov. 
1 
Nov. 
3 
2 
Jan. 
12 
7 1 
52 
Jan. 
21 
82 
9 
Nov. 
21 
Nov. 
26 
5 
Feb. 
5 
72 
79 
Feb. 
15 
87 
10 
Dec. 
2 
Dec. 
4 
2 
Feb. 
14 
73 
5 i 
... do. 
76 
1 Unfertilized female. 
THE EGG 
The egg (PI. 1, F) is opaque shining white, the surface somewhat roughened with 
minute raised spots; it varies considerably in shape but is usually somewhat spindle- 
shaped, with one end thicker and more rounded than the other. Length 0.46 to 
0.5 mm., width 0.14 to 0.16 mm. 
INCUBATION PERIOD 
The egg hatches in from 1 % to 2 days during the warm months of the 
year, but in winter the incubation period is lengthened to as many as 5 
days. 
The developing embryo may be seen near the center of the egg as a 
cloudy white oval body. As the embryo develops the contents of the 
egg draw away from the two ends of the tough chorion, which shrivels 
and wrinkles. In the process of hatching, the chorion is ruptured at the 
broad end of the egg and the young larva emerges. 
