Part VII] Beeson : Life History of Toon Borer. 
51 
1916. Throughout the months of June, July and August, toon 
shoots attacked by robusta larvae were collected in various localities in 
the Dehra Dun District, and kept in glass rearing cages in the insectary. 
The emergence of moths is tabulated below :— 
Table 25.— Emergence of Moths of the Third Generation , 1916. 
Date of Emergence. 
Number of 
Moths. 
August— 
1st 
1 
4th ... 
2 
6th ... 
2 
8th ... 
5 
9th 
4 
10th 
9 
11th 
10 
12th 
8 
13tn 
12 
14th 
16 
15 th 
18 
16th 
20 
17th 
19 
18th 
21 
19th 
17 
20th 
16 
21st 
18 
22nd 
10 
23rd 
11 
24th 
8 
Date of Emergence. 
Number of 
Moths. 
August— 
25th 
7 
26th 
5 
27th 
6 
28th 
9 
29th 
6 
30th 
4 
31st 
3 
September— 
2nd 
2 
4th . . 
3 
7th 
3 
11th 
3 
12th 
2 
13th 
3 
14th 
4 
18th 
3 
22nd 
2 
23rd 
5 
28th 
1 
29th 
1 
The earliest moths appeared in the rearing cages on the 1st August 
and the latest on the 29th September, with a general maximum emer¬ 
gence between the 8th and the 31st August. These results agree gener¬ 
ally with those obtained on a smaller scale in 1915, but it is probable 
that some of the moths which appeared in the breeding cages late in 
September may represent early broods of the fourth generation. It is 
not possible to differentiate material obtained in the field during the 
critical period. 
In Plate VIII the emergence of the 1916 moths is shown in a curve 
constructed from the progressive daily totals. 
4. The Fourth Generation. 
Larvae of the Fourth Generation- 
1915. The field-work carried out in August and September gave 
some indication of the boundaries between the 3rd and 4th generations 
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