27 
eggs. The wri toT was una])le to secure eggs in this wa}'. In onl}- 
two instances has the writer made definite observations on the number 
of eggs laid by a single female moth. Two pairs of moths were 
secured in copula and placed in separate limb cages. In one cage 21 
eggs were found, but as the moth escaped the observation was incon- 
clusive. In the other cage 25 eggs were laid, but a spider put an end 
to the experiment before a definite conclusion was reached. In view 
of these incomplete observations the writer can only venture an 
opinion that the maximum number of eggs laid by one moth is about 
50, with the average between 30 and -10, which is comparable to defi- 
nite records of other insects of this family. 
THE EGG-LAYING PERIOD. 
Upon dissection of the ovaries of the female of the codling moth 
the eggs are found in various stages of development. It is also noted 
that eggs are laid Avhen they are in different stages of maturity. 
From these facts we ma}^ conclude that the egg-laying period extends 
over some time. Various authors have given the length of time from 
the emergence of the moth to the beginning of the laying of the eggs 
as from 48 hours to 6 or 8 days. Professor Gillette gives the time as 
al)out 5 da3^s. The various records of writers show that this time 
varies from 2 to 7 days, with an average of from 4 to 5 days. 
DURATION OF EGG STAGE. 
In 1746 Roesel stated that the egg hatched in 8 days. Recent authors 
give the length of the stage as follows: Le Baron, one week: Wash- 
burn, 5 to 10 days; Rile3% 4 to 10 daj^s; Slingerland, one week; Card. 
8 to 10 days; and Professor Gillette, to 8 days' in his lal^oratorv. 
with a known temperature, and in the orchard one day longer. CooU\v 
records 12 da3^s as the length of the stage of one egg. 
The results of observations upon KU eggs and observations of Pro- 
fessor Cordley are given in Table I, with the total and average effect- 
ive temperature to which the (\o-gs were subjected. 
T. 
UU.E I. 
— Dnntfion of ( 
Oil >^t(t<l(' ( 
)l ('(xflltKJ IHO/ll. 
Date laid 
Number 
laid. 
i 
Date 
hatched. 
Number 
hatched. 
Period of 
incuba- 
tion. 
Total ef- 
fective 
tempera- 
ture. 
Average 
elTective 
tempera- 
ture. 
May ;5() — 
Aug. 11 ... 
1902. 
21 
1 
1902. 
Juue 11 
June 12 
Juue 13 
1 
3 
17 
Dai/g. 
13 
14 
22S 
2ri;i 
347 
•^ F. 
19 
19 
24.7 
Aug. 12 ... 
Aug. 21 
Aug. 28 
Aug. 25 
Sept. 5 
Sept. r. 
8- 
5 
(■> 
t) 
8 
9 
12 
li 
12 
2tH; 
2i;(". 
217 
217 
.",.V" 
Aug. 1() 
9 
Aug. 2(; 
28 
