44 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 11 
Length of the Egg Stage 
The length of the egg stage in spring and in summer varied. In the 
insectary in May, 1914, eggs hatched in 11.1 days, an average from 
104 eggs, according to notes by the writer. In July and August, 1914, 
much less time was required; 115 eggs hatched in 5.5 days (average). 
The range was from 3 to 8 days. 
In July and August, 1915, more time was required and an average 
of 8.5 days resulted in computing the data from 108 eggs. August, 
1915 was the coolest August on record and July, 1915, with one excep¬ 
tion, the coolest, so that the effect of temperature is clearly evident 
here. The range in 1915 was from 3 to 12 days. 
On the contrary July, 1914 was, with one exception, the warmest 
July on record. Two extremes of temperature then have affected 
these records of the length of the egg stage. 
Only one accurate record is available for July, 1916, when 21 eggs 
hatched in 5 days. 
Number of Eggs Deposited by One Female 
No one has previously given any records of the number of eggs 
deposited by a single female, so far as the writer is aware. Single 
pairs of moths were placed under large glass lantern globes which 
enclosed growing strawberry plants and daily records were made of 
all eggs deposited in the cages. 
The records of 35 female moths indicate an average of 72.9 eggs per 
female. This average is undoubtedly low, because some moths died 
soon after being placed in the cage and consequently did not deposit 
a normal number of eggs. 
The highest number of eggs deposited by one female was 136, accord¬ 
ing to a record by J. L. Horsfall in August, 1916. The lowest number 
was 12. In this last case the moth died the seventh day after being 
placed in the cage. 
The Larval Stages 
Newly hatched larvae are about 1.5 mm. long. Four larval stages 
were determined by W. 0. Ellis in the insectary in 1914. Single newly 
hatched larvae were isolated in glass vials, fed on strawberry foliage, 
and the growth carefully observed from day to day. 
Measurements of the head widths were made after each moult and 
recorded. From all the data accessible head width measurements of 
the four stages averaged as follows: Stage I, .22 mm.; Stage II, .33 
mm.; Stage III, .59 mm.; Stage IV, .85 mm. 
In 16 cases accurate records of the length of the entire larval stage, 
egg to the pupa, were secured. These averaged 19.8 days, from larvae 
reared in July and August. 
