20 
Indian Forest Records. 
[Vol. VII. 
PART IV. 
SEASONAL HISTORY STUDIES. 
1. Seasonal History in Dehra Dun, U. P. 
1. The First Generation. 
A generation of the insect as we have defined it on p. 13 is considered 
to commence with the egg stage and terminate with the moth stage ; 
but in order to obtain a starting-off point for a consideration of the 
first generation, it is necessary to record initially the emergence period 
of the moths of the fifth or overwintering generation, since these moths 
produce the eggs of the first generation. 
The spring brood of moths (5th Generation). 
Material for emergence records of the first, spring, brood of moths 
(fifth generation) was collected in the form of shoots of toon containing 
larva 3 from various localities in the neighbourhood of Dehra Dun. The 
infested shoots were kept under different conditions of temperature and 
humidity,to determine the influence of these factors on the length of the 
pupal period and the emergence of the moth ; the experiments are dealt 
with in the section of the fifth generation larvse. The table below shows 
the comparative emergence period of fifth generation moths in 1914-16. 
Table 2. —Bates of emergence of moths of the spring brood (Fifth Genera¬ 
tion) in 1914, 1915 and 1916. 
1914. 
1915. 
1916. 
Total 
Date of Emergence. 
Number of 
moths. 
Number of 
moths. 
Number of 
moths. 
number of 
moths. 
February— 
18t«h. 
2 
2 
22nd ...... 
, 
1 
1 
23rd. 
• • 
24th. 
.. 
.. 
.. 
25th. 
1 
1 
26th. 
.. 
i 
27th. 
i 
28th. 
i 
• • 
•29th. 
• • 
i 
[ 165 ] 
