14 BULLETIN 1336, U. S. DEPARTMENT OF AGRICULTURE 
Table 8. — Length of pupal stage of the green clover worm 1 
No. 
Date of 
pupation 
Date of 
emerg- 
ence 
Number 
of days 
No. 
Date of 
pupation 
Date of 
emerg- 
ence 
Number 
of days 
1 
May 20 
do .. 
May 30 
May 31 
June 27 
June 28 
June 29 
June 30 
July 1 
July 10 
July 12 
...do 
...do 
July 13 
10 
11 
8 
9 
7 
8 
8 
9 
11 
10 
7 
8 
13 
Aug. 12 
Aug. 14 
Aug. 25 
Sept. 1 
do 
Aug. 24 
Aug. 23 
Sept. 8 
Sept. 15 
Sept. 21 
Oct. 28 
Oct. 29 
Nov. 3 
12 
2 
14 
15 
9 
3 
June 19 
...do 
June 22 
...do 
14 
4 
16 
17 
14 
20 
G 
18 i Oct. 4 
19 Oct. 6 
24 
7 
June 23 
July 1 
do 
23 
8 
20 
Oct. 14 
20 
9 
10.. 
July 2 
July 5 
...do 
12 1 
11 
Maximum _. 
24 
12 . 
7 
1 The data for the months of June and July were obtained by F. M. Moody. 
SUMMARY OF LIFE CYCLE 
The egg-laying period of the moth may last for a period of 11 
days or more, the egg hatching during the summer and early fall in 
about 4 days. The larval period lasts about 23 days, in the course 
of which the caterpillar molts five times and spends approximately 
two days as a prepupa inside the cocoon. The pupal period lasts 
from 7 to 24 days, except when lengthened by hibernation. Table 9 
gives the average lengths of the different stages. 
Table 9.- 
—Summary of duration of stages of development of the green clover worm 
Stage 
Average 
period 
Egg 
Days 
3.88 
Larva . 
22.84 
12.10 
Pupa.. . 
Total 
38.81 
SEASONAL HISTORY 
NUMBER OF GENERATIONS A YEAR 
During the season of 1916 at Knoxville, Tenn., four distinct 
generations were found to occur. Certain heavily infested alfalfa 
fields on the farm of the State Agricultral Experiment Station were 
visited every few days, and records were kept of the varying abund- 
ance of the different stages of this species. Parts of these fields were 
standing throughout the season, which eliminated the interference 
of cutting with the development of the generations. Figure 14 
APRIL 
HAY 
JUNE 
TUU 
AUGUST 
SEPTEMBER 
OCTOBER 
^^^ ~ 
,<<^>„_<< < ^^<^ ^ 
■NVANVsNNWI Adult stage. 
Immature stages, 
Fig. 14.— Diagram showing the number of generations of the green clover worm dining the year 1916 at 
Knoxville, Tenn. 
