THE POTATO TUBER MOTH. 
Table 6. — Oviposition of the potato tuber moth by virgin females. 
27 
Female No. 
Period 
between 
emerg- 
ence and 
ovi- 
position. 
Total 
number 
eggs. 
Period 
of ovi- 
position. 
Length 
of life. 
1 
Days. 
1 
3 
7 
4 
5 
5 
4 
13 
51 
6 
44 
1 
18 
29 
9 

32 
Days. 
7 
1 
5 
9 
1 
16 
13 
6 
Days. 
17 
2 
13 
22 
11 
21 
18 
12 
28 
17 
2 
3 
4 
5 
6.. : 
7 
8 
9 .. 
10 J 
6 
10. 
Examination of this table will show also that oviposition was 
delayed longer after emergence than in the case of fertilized females. 
POSSIBLE PARTHENOGENESIS. 
To corroborate the observations on parthenogenesis cited by 
Picard regarding this insect (83), unfertilized females were isolated 
during spring and fall, and all the eggs deposited were carefully 
watched. In these experiments 54 females deposited a total of 
486 eggs, of which 324 were laid during September and 162 during 
April and May. None of the eggs hatched, showing that while 
parthenogenesis may exist, it is not very common. 
LENGTH OF LIFE. 
Pairs of adults isolated proved that the length of life of the male 
is shorter than that of the female. This proved to be the case in 221 
out of 275 experiments carried out for egg records. In nearly every 
case where the female died first the egg record was poor, indicating 
that the female was abnormal to begin with. The length of life 
varies with the temperature, the warmest season giving the shortest 
life records. This is even more pronounced where the adults are 
not fed. 
The extremes noted for length of life were, for the male 1 to 14 
days, and for the female 2 to 22 days, in cases where the pairs had 
mated. In experiments using unmated individuals the length of life 
for the male varied from 3 to 31 days, and for the female, 2 to 28 days. 
In the case of the male which lived 31 days no food was given, and 
the individual was kept in a dry vial. This record was made during 
November when the weather was cool. 
