42 
Indian Forest Records. 
[Vol. VII. 
1915. The evidence obtained in the following year 1915 is founded 
on material collected under sack-bands put out on 335 trees in the neigh¬ 
bourhood of Dehra Dun. The cocoons were collected from the sack- 
bands at regular intervals and kept in glass box-form breeding cages 
in the insectary. The amalgamated emergence records are given in 
Table 19. 
Table 19 .—Emergence of Moths of the Second Generation, 1915. 
Time of Emergence. 
Total 
Emergence. 
Time of Emergence. 
Total 
Emergence. 
May— 
June— 
18th 
4 
2nd 
36 
19th 
4 
3rd 
85 
20th 
6 
4th . . 
51 
21st 
21 
5th . . 
55 
w 22nd 
16 
7th . . 
10 
24th 
14 
8th . . 
63 
25th 
31 
9th . . 
5 
26th 
37 
10th 
8 
27th 
72 
12th 
1 
28th 
43 
14th 
1 
31st 
55 
16th 
1 
June— 
18th 
3 
1st 
41 
19th 
5 
The earliest records for second generation moths obtained this year 
is the 18th of May and the latest the 19th of June, with the maximum 
emergence between the 25th May and the 18th June, which agrees gener¬ 
ally with the records of 1914. The true extent of the generation is, 
however, not represented, as from experiments carried out in 1916, it 
is evident that the sack-bands were put up a fortnight to three weeks 
too late to secure the earliest individuals of the brood. Moreover, 
the number of moths reared is a very small proportion of the total 
number of cocoons collected ; the mortality is due to two causes : (a) 
a large number of mature larva3 and cocoons was reared in wire cages 
in the open and heavy rainfall on one night swamped the cages and 
drowned over 3,000 insects ; and, (b) owing to overcrowding of cocoons 
in glass-sided cages a very large percentage of moths died in the act of 
emergence. It was found that if large numbers of larvse are confined 
in small cages, they spin a very dense network of silk webbing while 
wandering about the cages, so that the sides of the cage and the cocoons 
of previously pupated individuals are covered with impenetrable sheets 
of silk several layers deep. The moth when ready to emerge is unable 
to pass through the silk webbing and dies without effecting emergence. 
1916. Special attention was paid to the elimination of this difficulty 
when repeating the rearing operations in 1916. Collections of larvse 
and cocoons were made daily in March, April and May from about 
[ 187 ] 
