Part VII] Beeson : Life History of Toon Borer. 
43 
898 sack-banded trees in the vicinity of Dehra Dun. The material 
obtained on each tree was counted on the spot, and brought in sealed 
boxes to the insectary and distributed in more than 100 separate breeding 
cages. Facilities for pupation were given in the form of rolls and spirals 
of stiff paper and folded sheets of corrugated packing-cardboard. The 
tendency to wander and spin silk was much reduced, but in spite of all 
precautions a large proportion of the insects died as a result of rough¬ 
handling and overcrowding. Out of a total of about 77,000 larvae 
and pupae collected under sack-bands (representing both the first and 
the second generations), only 30,848 moths emerged successfully in the 
rearing cages. Over 28,000 larvae and pupae were counted dead inside 
the cages at the close of the experiment and the remainder were either 
parasitised or died as moths in the cocoons. The conditions pro¬ 
ducing mortality among larvae, pupae and moths, however, were 
constant throughout the period of the experiment and the actual emer¬ 
gences recorded may, therefore, be taken as an approximately correct 
indication of the seasonal history of the two generations. 
As the flight periods of the first and second generations overlap, the 
emergence records of both are given in one table, (see Table 20). 
Table 20.— Emergence of Moths of the First and Second Generations , 
from Material collected under Sack-hands, Dehra Dun 1916. 
Date 
of 
Emergence. 
1 
Number 
of 
Moths. 
Date 
of 
Emergence. 
Number 
of 
Moths. 
Date 
of 
Emergence. 
Number 
of 
Moths. 
April— 
8th . 
30 
April— 
28th . 
48 
May— 
18th . 
628 
9th . 
57 
29th . 
7 
19th . 
875 
10th . 
115 
30th . 
4 
20th . 
874 
11th 
237 
May— 
1st 
29 
21st . 
669 
12th 
814 
2nd . 
9 
22nd . 
526 
13th . 
1,645 
3rd 
3 
23rd . 
313 
14th . 
1,476 
4th 
10 
24th . 
119 
15th . 
1,454 
5th . 
22 
25th . 
168 
16th . 
2,471 
6th . 
49 
26th . 
102 
17th . 
2,979 
7th 
47 
27th . 
49 
18th . 
2,393 
8th . 
92 
28th . 
18 
• 19th . 
2,137 
9th 
116 
29th . 
6 
20th . 
2,027 
10th 
119 
30th . 
25 
21st 
1,558 
11th 
89 
31st . 
3 
22nd 
1,259 
12th 
139 
June— 
1st . 
2 
23rd 
848 
13th 
326 
2nd . 
4 
24th 
817 
14th 
495 
3rd . 
25th . 
429 
15 th 
467 
4th . 
i 
26th 
296 
16 th 
523 
5th . 
1 
27th . 
123 
17th 
644 
6th . 
• * 
[ 188 ] 
