8 BULLETIN iKA), U. S. DEPARTMENT OF AGRICULTURE. 
DURATION OF FIRST LARVAL STAGE. 
The duration of the first larval stage of 72 individuals reared 
varied from 8 to 12 days with an average of 9.19 days. These data 
are shown in Table IV. Records of this stage cover the period from 
June 2, the earliest recorded date of hatching, to June 24, the latest 
recorded date of passing the first molt. 
Table IV. — Duration of first lar- 
val stage of grapevine loo per, 
Xorth East, Pa.. 1917. 
Number 
Duration 
of larvae. 
ol stage. 
Days. 
IS 
8 
34 
9 
12 
10 
4 
11 
4 
12 
l 70 
- 9. 19 
Table V. — Duration of second lar- 
val stage of grapevine looper, 
Xorth East, Pa.. 1917. 
Number Duration 
of larvae. of stage. 
35 
12 
5 
1 
Days. 
8 
9 
10 
11 
167 
2S.16 
i Total. 
Weighted average. 
Total. 
T\ eighted average. 
DURATION OF SECOND LARVAL STAGE. 
The duration of the second larval stage, of 67 individuals reared, 
varied from 7 to 11 days with an average of 8.16 days. With the 
exception of one second-stage larva collected June 2, records on this 
stage extended from June 10, when the first larva passed the first 
molt, to July 2, when the latest larva passed the second molt. Data 
relating to the duration of this stage are summarized in Table V. 
Table VI. — Duration of third 
larval stage of grapevine looper. 
Xorth East. Pa.. 1917. 
Number 
of Ian- a?. 
Duration 
of stage. 
1 
7 
16 
24 
12 
3 
4 
Days. 
6 
8 
9 
10 
11 
12 
167 
- B. 95 
i Total. 
Weighted average. 
DURATION OF THIRD LARVAL STAGE. 
The duration of the third lar- 
val stage, of 67 individuals reared, 
varied from 6 to 12 days with an 
average of 8.95 days. These data 
are summarized in Table VI. The 
records on this stage extended 
from June 19, when the earliest 
larva passed the second molt, to 
July 11, when the latest passed the 
third molt. 
