30 
Indian Forest Records. 
[Vol. VII. 
From the records given above, it is evident that the development of 
the larva of the 2nd generation is relatively rapid, and that there are 
3 moults before pupation. The time taken to pass from the first to the 
second stage is 4 days ; from the second stage to the third, 2 days ; from 
the third stage to the fourth, 2 days ; and from the fourth stage to the 
pupa, 4 days. The time required for the construction of the silk cocoon 
in which the larva pupates is 1 to 2 days. The feeding period of the 
larva varies from 9 to 11 days, vide examples 26, 31, 33a, and 36 in 
Table 8. A period of about 1 to 2 days should be allowed for the 
interval between hatching and collection in the field, which gives a 
total feeding period for the larva of this generation, as approximately 
10—13 days. 
Number of fruits eaten by a single larva. 
On the 10th May 1915, a typically attacked panicle of fruits was 
collected and examined ; it was found to contain— 
4 full-grown bluish green, 4th stage larvae. 
4 ,, ,, reddish green, 3rd stage larvae. 
7 ,, ,, brown, 2nd stage larvae. 
2 ,, ,, pale brown, 1st stage larvae. 
The number of attacked and completely eaten fruits in the bunch 
was 57. The larvae from this source were kept in a cage with 17 fresh 
fruits. On examination three days later, on the 13th May, it was found 
that 4 larvae had pupated, and that out of the 17 fruits, 13 were 
completely consumed. Ten fresh fruits were added. By the 19th May, 
all larvae except one had pupated, and out of the 10 fruits 9 were 
completely devoured, and the 10th partially eaten. Thus 17 larvae ate 
in all 90 fruits, i.e ., an average of 5—6 fruits per head. 
Swarming of the 2nd Generation Larvae. 
In May 1915, it was realised that robusta larvae which have completed 
their development in toon fruits normally display a tendency to migra¬ 
tion, in the search for suitable places in which to pupate. Under ordinary 
conditions pupation occurs in crevices, or under flakes of the bark of the 
tree on which they have fed. Attempts were, therefore, made to obtain 
incidence data by means of artificially induced pupation in bands of sack¬ 
ing, folded double and tied to the trunk of the tree with twine. Some 
335 toon trees in avenues and gardens in Dehra Dun were banded at 
various dates in May 1915, and collections of mature larvse and cocoons 
were carried out when pressure of other work permitted. Four localities 
were selected,mz. :—Locality I, 67 trees banded on the 12th, 15th and 
18th May ; Locality II, 188 trees banded 19th—28th May; Locality 
[ 175 ] 
